Court Opinion

ID: 2680959
Source: CourtListenerOpinion
Date Created: 2014-06-27 21:04:42.169988+00
Date Added: 2024-06-11T13:15:07.261554
License: Public Domain

Christopher D. Hamilton, et al. v. Benjamin Kirson, et ux., No. 78, September Term,
2013.

Candace Renee Alston, et al. v. 2700 Virginia Avenue Associates, et al., No. 100,
September Term, 2013.

NEGLIGENCE—LEAD-PAINT POISONING—CIRCUMSTANTIAL EVIDENCE
Lead-paint poisoned plaintiffs may prove the causation element of a prima facie
negligence case through purely circumstantial evidence. When doing so, however, the
plaintiff must put forth a theory of causation and sufficient supporting evidence that, if
believed, would permit a jury to draw the necessary logical inferences of the presence of
lead-based paint on the premises at the relevant time(s). In the present summary
judgment cases, the evidence was insufficient to infer that the defendants’ conduct was a
substantial factor in bringing about the alleged injuries because the plaintiffs failed to put
forth evidence that the subject properties contained lead-based paint at the relevant
time(s).

NEGLIGENCE—CIRCUMSTANTIAL EVIDENCE—EXPERT TESTIMONY
In order for expert testimony to be admissible, a sufficient factual basis must support the
expert’s opinion so that the opinion does not amount to conjecture, speculation, or
incompetent evidence. In these cases, the experts had an insufficient factual basis from
which to reach the conclusion that the subject properties contained lead-based paint and
were a substantial contributor to the plaintiffs’ injuries.
Argued 3 April 2014

                                     IN THE COURT OF APPEALS OF
                                             MARYLAND

Circuit Court for Baltimore City        No. 78, September Term, 2013
Case No. 24-C-09-003482
                                   CHRISTOPHER D. HAMILTON, ET AL.

                                                        v.

                                        BENJAMIN KIRSON, ET UX.

Circuit Court for Baltimore City       No. 100, September Term, 2013
Case No. 24-C-10-000721
                                    CANDACE RENEE ALSTON, ET AL.

                                                        v.

                                          2700 VIRGINIA AVENUE
                                            ASSOCIATES, ET AL.

                                    Barbera, C.J.,
                                    Harrell,
                                    Battaglia,
                                    Greene,
                                    Adkins,
                                    McDonald,
                                    Wilner, Alan M. (Retired,
                                                   Specially Assigned),

                                                  JJ.

                                             Opinion by Harrell, J.

                                     Filed: June 20, 2014
       We consolidate these two cases, Hamilton v. Kirson, No. 78, September Term,

2013, and Alston v. 2700 Virginia Avenue Associates, No. 100, September Term, 2013,

for purposes of this opinion. In each case, a plaintiff or plaintiffs brought, among other

claims, 1 a negligence action against landlords to recover for his or her injuries resulting

from lead paint poisoning. 2 Neither plaintiff adduced direct evidence that the respective

demised premise was a substantial contributor to the injuries or that the interiors of the

homes contained lead paint, but rather relied on circumstantial evidence in an effort to

satisfy the causation element of a prima facie negligence claim. After discovery was

conducted, the landlords filed motions for summary judgment, which the Circuit Court

for Baltimore City granted. In both cases, the trial judges reasoned that the respective

plaintiffs failed to produce sufficient evidence to present a prima facie negligence case

with regard to the causation element. Our review on appeal focuses on evaluating what

quantum or quality of circumstantial evidence in lead paint poisoning cases is sufficient

to satisfy the causation element of a prima facie negligence claim, so as to submit the

case to the fact-finder.

       1
         Each case alleged an additional count of unfair trade practices, in violation of the
Maryland Consumer Protection Act (“CPA”), see Md. Code (1975, 2005 Repl. Vol.),
Commercial Law Article, § 13-301, et seq., for leasing premises containing lead paint.
Because the parties did not raise any issue regarding these counts on appeal, we do not
discuss these claims further and focus solely on the negligence counts.
       2
           Both cases were initiated by the victims after they reached adulthood.
       Because the facts and issues presented in the consolidated cases differ slightly, we

set forth first the background of each case. Then, we shall address collectively the shared

relevant legal precedents, applying the relevant case law and legal principles to each case.

       I.     BACKGROUND

              A. Alston v. 2700 Virginia Avenue Assocs.

       On 26 January 2010, Candace Alston filed suit in the Circuit Court for Baltimore

City against 2700 Virginia Avenue Associates, Theodore Julio, Lawrence Julio, and

others, alleging that the defendants acted negligently as landlords in providing premises

containing chipping, peeling, and flaking lead paint in violation of the Baltimore City

Housing Code (hereinafter, “Housing Code”). 3          Subsequently, an Amendment by

Interlineation added to the causes of action Brian Alston (Candace’s sibling) and his

claims. The Complaint and amendments alleged that Candace and Brian (hereinafter,

collectively the “Alstons”) suffered lead-based paint poisoning, Candace while residing

       3
         Although not specifically identified in the Complaint, we presume by how the
case unfolded that the relevant provisions are Housing Code, Baltimore City Code (2000
Repl. Vol.), Art. 13, § 702, 703 & 706. Section 702 requires that “[e]very building . . .
occupied as a dwelling shall, while in use . . . be kept in good repair, in safe condition,
and fit for human habitation.” Section 703 provides, in relevant part, that “good repair
and safe condition shall include . . . [a]ll walls, ceilings, woodwork, doors and windows
shall be kept clean and free of any flaking, loose, or peeling paint.” Next, section 706
requires that (1) “[a]ll interior loose or peeling wall covering or paint shall be removed
and the exposed surface shall be placed in a smooth and sanitary condition,” and (2) “[n]o
paint shall be used for interior painting of any dwelling . . . unless the paint is free from
any lead pigment.”

                                            -2-
for consecutive periods at dwellings located at 2752 Virginia Avenue and 2810 Virginia

Avenue and Brian at 2752 Virginia Avenue.

      For her part, the Alstons’ mother, Leslie Sidbury, could not remember the exact

time periods and locations of their residences during the relevant times. The Complaint

alleged that the Alstons’ mother and her children resided at a number of properties

between 1989 and 1995. Specifically, Candace, who was born on 27 January 1989,

“lived in the dwelling or frequented the dwelling as an invitee of the tenant during 1989-

1995” for the following properties: (1) 3006 Woodland Avenue; (2) 3501 Oakmont

Avenue; (3) 303 N. Gilmor Street; (4) 2752 Virginia Avenue; and, (5) 2810 Virginia

Avenue.

      Subsequently, in the Amendment by Interlineation adding as a victim Brian

Alston, who was born on 13 August 1990, the Alstons narrowed the matter somewhat

that their mother lived at the 2810 Virginia Avenue property between 1992-1993. Then,

they lived as a family at 2752 Virginia Avenue between 1993-1995.             During the

defendants’ later deposition of Ms. Sidbury, it was discovered that she did not remember

the exact location of their residence, but approximated that the house was located in the

2800 block on Virginia Avenue. Plaintiffs’ blood lead level testing slips listed, however,

only 3006 Woodland Avenue as their address.

          During discovery, the Alstons identified Dr. Michael Weitzman as their expert

witness. Dr. Weitzman opined, relying on circumstantial evidence solely, that 2752

Virginia Avenue and 2810 Virginia Avenue (hereinafter, the “subject properties”) were a

source of, and a substantial contributing factor to, the Alstons’ lead paint poisoning and

                                           -3-
resulting injuries. To support this opinion, Dr. Weitzman relied on the following facts:

(1) the Alstons lived in and/or visited the subject properties during the time period that

they demonstrated elevated blood lead levels; (2) the residences had chipping, peeling, or

flaking paint during the relevant time period; (3) the residences were older homes in

Baltimore, built before 1979; 4 and (4) the Alstons exhibited elevated blood lead levels at

the time they lived in the subject properties. No scientific testing was conducted of the

paint (chipping, flaking, peeling, or otherwise) at the residences for the presence of lead.

       Defendants (Respondents here) filed a Motion for Summary Judgment on 22

December 2010, arguing that the Plaintiffs “failed to sustain their burden of proving that

they were exposed to and ingested chipping, peeling, or flaking lead-based paint in

violation of the Baltimore City Housing Code at the Defendants’ properties . . . .”

Specifically, Respondents argued that Plaintiffs’ expert relied on insufficient assumptions

to provide a factual basis for his opinion that Plaintiffs were exposed to a lead paint

hazard at Defendants’ properties.      Respondents emphasized that there is no direct

evidence that Plaintiffs resided at Defendants’ properties or “that Defendants’ properties

contained lead paint hazards, or defective lead-based paint, during Plaintiffs’ alleged

tenancy at the properties.” Moreover, Respondents pointed out that “Plaintiffs’ source

expert also cannot eliminate [other] potential source[s] of Plaintiffs’ recorded [blood]

       4
         According to the deposition of Dr. Weitzman, he found the age of the house
relevant because the State of Maryland issued a report finding that 75% of houses in
Baltimore City were likely to have lead-based paint if built between 1950 and 1978. In
1978, lead-based paint was banned. This report was not included in the record.

                                             -4-
lead levels, which precludes Plaintiffs from providing adequate circumstantial evidence

of exposure at the properties.”

       After a hearing on the motion on 6 February 2012, the trial judge granted

summary judgment, stating:

       In this case, the identification of the address is an interesting issue. I’m not
       going to grant summary judgment on that basis, because I believe that the
       plaintiff has come up – has come forward with, it may be the barest
       showing, but it’s a bare showing to tie herself to these two addresses on
       Virginia Avenue.

       And this is unlike a case where the defendant comes forward with sworn
       statements in whatever form; interrogatories, affidavits, depositions that
       refute any possibility that the plaintiff actually lived or spent time at those
       addresses.

       So although it is extremely sketchy in this case, both the identification of
       the specific properties and the years when the plaintiffs were living there, I
       don’t think the defendant prevails on that basis.

       I do think the defendant prevails on the basis that as to these
       properties the plaintiffs cannot show the requisite causation of any
       elevated blood lead levels derived from these properties.

       I accept that the plaintiffs have shown that there was deteriorating paint at
       the properties. And I will even, for purposes of the motion go so far as to
       accept that the plaintiffs have shown that they exhibited elevated blood lead
       levels at around the time that they say they were living in these properties.
       What is missing is evidence that would tie those elevated blood lead
       levels to the specific conditions in these properties. And I accept the
       possibility that that could be proven indirectly by circumstantial
       means.

       But I think the essential logical ingredient that must be present in order for
       Dow or a theory like Dow to apply is that logically there must be a -- a
       very strong conclusion that the lead that the plaintiffs were
       experiencing had to come from this source because there is no other
       logical source that is available.

                                             -5-
      Now, there may be a number of ways that could be done. I’ve suggested
      one of them would be if there were visitation properties, that there is some
      evidence that tends to exclude those.

      There might be evidence that the paint wasn’t deteriorating in those. There
      might be evidence that they were built after a period when lead paint was
      likely present. There might be evidence that the visits were very short,
      were supervised closely and the children didn’t ingest paint. There may be
      a number of bases that might be advanced by plaintiff.

      But here you simply have two wide open possible properties at the
      same time, either of which could have been the source of the lead that
      is alleged. And that is insufficient to establish the prima facie case that
      the plaintiff would have to show on negligence.

                                           ...

      For those reasons, I think that the moving defendants with respect to these
      two addresses on Virginia Avenue are entitled to summary judgment. And
      I’ll grant summary judgment as to both plaintiffs as to these defendants.

(Emphasis added.) The trial judge issued a written order to like effect, stating that the

Motion for Summary Judgment was granted “[f]or the reasons stated on the record at the

hearing.”

      Plaintiffs appealed timely to the Court of Special Appeals. The intermediate

appellate court affirmed the judgment of the trial court in an unreported opinion filed on

10 July 2013. Plaintiffs-Petitioners filed a Petition for a Writ of Certiorari, which this

Court granted, 435 Md. 266, 77 A.3d 1084 (2013), to consider the following questions:

      (1) By following its decision in West v. Rochkind, 212 Md. App. 164, 66
A.3d 1145 (2013), did [the] CSA [Court of Special Appeals] [here]
      improperly undermine the common law principle that the law makes no
      distinction between the weight to be given to circumstantial evidence and
      direct evidence and that no greater degree of certainty is required of
      circumstantial evidence than of direct evidence?

                                           -6-
      (2) Did [the] CSA’s decision in West improperly change a Plaintiff’s
      burden of proof in a circumstantial evidence case from “preponderance of
      the evidence” to greater than “beyond a reasonable doubt?”

      (3) Does [the] CSA’s holding improperly require a Plaintiff in a lead-paint
      case to prove that a given property was “the only possible explanation” for
      a Plaintiff’s injuries in order to make a circumstantial case?

             B. Hamilton v. Kirson

      On 28 May 2009, Christopher Hamilton filed in the Circuit Court for Baltimore

City his initial complaint alleging several negligence claims against Lola Singer, the

previous owner of property at 2231 Barclay Street (hereinafter, the “Singer property”),

and Benjamin and Karen Kirson (hereinafter, collectively the “Kirsons”), the previous

owners of property at 754 Bartlett Avenue (hereinafter, the “Kirson property” or the

“subject property”). According to the Complaint, these properties “contained lead-based

paint in such deteriorated conditions that it was peeling, chipping and flaking from the

walls, baseboards, windowsills and other areas of the premises,” as well as the presence

of lead paint dust and powder. It was alleged that Christopher, while living at these

residences, ingested lead-based paint chips and dust and, as a consequence, suffered

permanent brain damage resulting in developmental and behavioral injuries.          The

Complaint alleged that Christopher resided at 2231 Barclay Street from 1992-1993, and

at 754 Bartlett Avenue from 1993-1995.

      On 21 August 2009, the Complaint was amended to add a second plaintiff—

Christopher’s brother, Rickey—as well as additional defendants and allegations.

Specifically, the Hamiltons added allegations that they were exposed to lead-based paint

at 445 E. Lanvale Street, where they lived from 1991-1992 and which was owned and

                                          -7-
managed by Ralph Small and the Patella Realty Corporation, the added defendants. On 2

April 2010, the Hamiltons amended their complaint again to add allegations involving

two additional properties which Plaintiffs visited as children and which were owned and

managed by other newly-added defendants. 5

       Rickey was born on 5 April 1989. From his birth until approximately April of

1990, Rickey lived with his mother, maternal grandparents, sister, and uncle somewhere

on the 2300 block of Barclay Street. Rickey moved with the same family members to

445 East Lanvale Street approximately in the summer of 1990. A short time later, on 5

September 1990, Christopher was born and lived in the same house as Rickey from that

point in time. At some point in 1992, the family moved to 2231 Barclay Street where

they resided until approximately the fall of 1993, at which time the family moved again

to 754 Bartlett Avenue. The family lived at that address until some point in 1995. Then,

the family moved to 1604 Gorsuch Avenue, where they resided until 1998. Between

1990 and 1994, Rickey was tested six times for blood lead levels (“BLL”). Between

1991 and 1995, Christopher was tested nine times. The results of these tests are detailed

in the following chart:

       5
         Ultimately, due to a recognized lack of evidence regarding several of the
additional properties, the Hamiltons dismissed, prior to the summary judgment stage,
their claims against all defendants, save Singer and the Kirsons. Singer was not
dismissed as a defendant until after the Hamiltons noted an appeal to the Court of Special
Appeals. Thus, our discussion of the relevant facts focuses on the claims involving the
Kirson property primarily and the Singer property only to the extent relevant and
necessary.

                                           -8-
               DATE                  RICKEY’S RICKEY’S            CHRIS’     CHRIS’
                                       AGE      BLL                AGE        BLL

   2300 block of Barclay Street (5 April 1989 to approximately summer of 1990)
              ---                   Newborn         ---         ---        ---

                    445 East Lanvale Street (summer of 1990 to 1992)
           15 August 1990              17 mos.       NR            ---          ---
            10 April 1991              24 mos.       NR            ---          ---
             27 June 1991                ---          ---        9 mos.      7 mcg/dL
           6 February 1992               ---          ---       17 mos.      7 mcg/dL
            23 April 1992                ---          ---       19 mos.      8 mcg/dL

                 2231 Barclay Street* (some point in 1992 to fall of 1993)
           12 January 1993             45 mos.     12 mcg/dL          ---        ---
           26 March 1993               47 mos.     11 mcg/dL          ---        ---
            13 May 1993                  ---           ---         32 mos.   14 mcg/dL

                       754 Bartlett Avenue** (fall of 1993 to 1995)
          24 September 1993            53 mos.      14 mcg/dL       ---          ---
          10 November 1993               ---            ---       38 mos.    17 mcg/dL
           26 January 1994               ---            ---       41 mos.    15 mcg/dL
             12 May 1994                 ---            ---       44 mos.    15 mcg/dL
           28 October 1994             66 mos.      10 mcg/dL       ---          ---
           2 February 1995               ---            ---       53 mos.    11 mcg/dL
           11 October 1995               ---            ---       61 mos.    10 mcg/dL

                           1504 Gorsuch Avenue (1995 to 1998)
           13 March 1996              83 mos.     7 mcg/dL           ---        ---

* The 2231 Barclay house was owned by Singer.
** The 754 Bartlett Ave. house was owned by the Kirsons and is the subject of the
present appeal.
Shaded blocks represent those test results which indicate elevated blood lead levels. 6

      6
        Blood lead levels are measured in micrograms per deciliter. According to Dr.
Simon’s report, a child is considered to have elevated blood lead levels at 10 mcg/dL.

                                           -9-
       During discovery, the Hamiltons retained Arc Environmental, Inc., to survey the

754 Bartlett Avenue property for lead-based paint. On 4 March 2011, Arc tested (or

attempted to test) the property and issued a report of its findings on 9 March 2011.

According to the report, the X-ray fluorescence analyzer detected lead-based paint, above

the Maryland standard (>0.7 mg/cm2), 7 on four of the fourteen surfaces tested—the front

porch wall, the front window apron and casing, and the front basement window header.

The report noted that the property is “an occupied two story brick row home. The

inspector knocked on the front door of the property and spoke with a female resident who

stated that she has lived at the property for many years and subsequently denied the

inspectors [sic] request to test the interior of the property, but allowed exterior testing.”

       Additionally, as part of discovery, the Hamiltons identified Dr. Jacalyn Blackwell-

White, a board-certified pediatrician, as a medical causation expert and Dr. Robert Simon

as an industrial hygiene expert and environmental lead risk assessor. Drs. Blackwell-

White and Simon authored causation reports and were deposed.

       Dr. Blackwell-White opined:

       Rickey Hamilton experienced toxic levels of lead elevation during his
       younger years. Within a reasonable degree of medical probability, he
       suffered brain damage as a result of that exposure. The most likely
       source/sources of Rickey’s exposure include 2231 Barclay Street and 754

       7
         In Maryland, “lead-containing substance” is defined, in relevant part, as “any
paint, plaster or other surface coating material containing . . . more than 0.7 milligrams
per square centimeter by the X-ray fluorescence [‘XRF’] analyzer.” COMAR
26.02.07.02. According to the Arc Environmental report, where the XRF analyzer
provides a reading of 0.7mg/cm2 or less, the surface is classified as “negative,” and where
the reading is above the standard, the surface is classified as “positive.”

                                             -10-
      Bartlett Avenue. However, the visitation properties of 417 E. North
      Avenue and 510 E. 20th Street cannot be excluded. There was a paucity of
      descriptive interior surface information, lead paint information and details
      about the visits included concerning these properties.

With regard to Christopher Hamilton, Dr. Blackwell-White opined:

      It is my opinion that Christopher Hamilton was exposed to sustained levels
      of lead at an early age. The possible sources of Christopher’s lead exposure
      include 445 E. Lanvale Street, 2231 Barclay Street, 754 Bartlette [sic]
      Avenue, 417 E. North Avenue and 510 E. 20th Street. Based on the
      information available to me, more likely than not, Christopher was exposed
      to lead based paint at 2231 Barclay Street and 754 Bartlette [sic] Avenue
      because he experienced a significant rise in lead levels which was sustained
      during his residence at these two addresses. There was no significant
      change in blood lead level after moving from 2231 Barclay Street to 754
      Bartlette [sic] Avenue. There is not enough information available to me to
      implicate the Lanvale Street property over the visitation properties as a
      source of lead exposure for the first three lead level elevations. It is my
      opinion that within a reasonable degree of medical probability, he sustained
      brain damage as a result of early lead exposure and that his impairment is
      lifelong.

      Plaintiffs asked Dr. Simon “to determine if [Rickey’s and Christopher’s] residency

at 2231 Barclay Street and 754 Bartlett Street, Baltimore, MD, during their early

childhood, were substantial contributing sources of lead exposure during that time

period.” Dr. Simon stated that the 754 Bartlett Avenue house “was built in 1920 and

would more likely than not have had LBP [lead-based paint] based upon the age and use

of lead paint during that time period . . . .” 8 Moreover, Dr. Simon noted that the 754

      8
        Dr. Simon opined that “[t]he age of housing is important in the assessment of
presence of lead-based paint . . . .” The basis for this opinion was that:

      the Maryland Department of Environment which presumes that chipped,
      peeling, and flaking paint in housing built before 1950 contained lead. The

                                                                           Continued…
                                         -11-
Bartlett Avenue house contained paint in deteriorated condition.             Based on that

information, Dr. Simon concluded:

         [T]he residences at 2231 Barclay Street and 754 Bartlett Avenue,
         Baltimore, MD were the substantial, contributing locations and sources for
         elevated blood lead levels (EBLs) and lead poisoning exposure for both
         Ricky, Jr. [sic] and Christopher Hamilton during the first 6+ years of their
         childhoods. There was no indication in the data file that any other locations
         contributed to their EBLs [elevated blood lead levels] and lead poisoning
         during this time period.

         After discovery was completed, the Kirsons moved for summary judgment on

several grounds.       First, they argued that there was no Housing Code violation

demonstrating a negligent act on the part of Defendants and, thus, Plaintiffs did not have

an actionable negligence claim. Specifically, the Kirsons pointed out that Plaintiffs’

Cont’d

         USEPA [U.S. Environmental Protection Agency] has estimated that
         housing contained lead-based paint (LBP) based upon house age as listed
         below . . . .

               % Containing LBP            Built Age of Housing
               87%                         before 1940
               69%                         between 1940 to 1960
               24%                         between 1960-1978

Dr. Simon referred also to a press release on a report by the Maryland Department of the
Environment, which cited the U.S. Census Bureau as reporting that “95% of houses were
likely to have LBP if built before 1950 and that 75% of houses were likely to have LBP if
built between 1950 and 1978.” See Press Release, First Lady Hon. Kathleen O’Malley,
MDE Announce Results of Lead Poisoning Report (Aug. 27, 2010),
http://www.mde.state.md.us/programs/PressRoom/Pages/1296.aspx (referring to the
Maryland Department of the Environment, Childhood Blood Lead Surveillance in
Maryland Annual Report 2009 (Aug. 2010)).

                                             -12-
medical causation expert, Dr. Blackwell-White, stated that the blood lead levels were

consistent with exposure to airborne lead dust. Plaintiffs’ negligence claims, however,

are based on violations of the Housing Code’s prohibition of peeling or chipping paint.

       Second, the Kirsons argued that summary judgment was appropriate because there

was no direct evidence that the subject property was the source of the Hamiltons’ lead

poisoning and, moreover, Plaintiffs’ source experts’ opinions that the Hamiltons’ blood

lead levels were caused by exposure to lead hazards at the subject property, 754 Bartlett

Avenue, had an insufficient factual basis. The Kirsons maintained that, in order for the

Hamiltons to prove that the property had lead-based paint, testing was required for the

specific locations alleged as peeling, flaking, or chipping at the time of Plaintiffs’

elevated blood lead levels. The testing undertaken by Plaintiffs, however, was only of

locations on the exterior of the subject property. The Hamiltons’ mother stated in her

deposition that the exterior of the house was not in disrepair and, thus, according to the

Kirsons, the Hamiltons failed to produce the direct evidence that they were exposed to

hazardous lead-based paint at the subject property.

       Moreover, the Kirsons argued that the Hamiltons’ experts based their opinions of

the source of the Hamiltons’ lead exposure on the assumption that, if the exterior of the

house had lead paint, the interior of the house also contained lead-paint. According to the

Kirsons, the experts based this assumption (and, therefore, their opinions) on the age of

the house, the condition of the house, and the age and recorded blood lead levels of the

Hamiltons at the time of the tenancy.         Such assumptions, it was claimed, were

insufficient to form the factual basis of an expert opinion. Additionally, the Kirsons

                                           -13-
contended that the Hamiltons’ source experts lacked a sufficient factual basis to conclude

that the subject property was the source because they “did not rule out other potential

sources of Plaintiffs’ blood lead levels that were recorded while they lived at [the subject

property].” Specifically, the Kirsons pointed out that the Hamiltons’ source experts

failed to consider the three other properties that the Hamiltons visited frequently or lived

in during the time period before and during their lead poisoning 9 and failed to rule out

that the blood lead levels were the result of environmental or ambient sources, even

though both experts acknowledged that lead poisoning may be caused by these other

sources.

       The Hamiltons filed a Response in Opposition to the Kirsons’ Motion for

Summary Judgment, insisting that a sufficient factual basis existed to support the

opinions of their experts. The Hamiltons emphasized that experts are permitted to use a

combination of direct and circumstantial evidence to support their opinions.          They

maintained that, particularly in cases such as lead-paint poisoning, where often injured

persons do not have the ability to obtain direct evidence through testing of the properties

contemporaneously with their tenancy or afterwards in certain circumstances,

       9
         According to the Kirsons, Dr. Blackwell-White acknowledged that she could not
rule out the three visitation properties because she lacked the information necessary to
make that determination. Dr. Simon stated that, even though he assessed typically
visitation properties when he performed lead risk assessments in the past, he was not
provided with any environmental information regarding the other properties in this case.

                                           -14-
circumstantial evidence is the only recourse.         Specifically, in this case, the Hamiltons

stated:

           [T]he subject property was built in 1920, circumstantially leading to a
          finding that the structure contained lead-based paint. Both Christopher and
          Rickey Hamilton ate paint chips while living there. During their tenancy,
          Plaintiffs’ blood lead levels remained elevated; significant because of Dr.
          Simon’s testimony regarding the half-life of lead in a person’s blood.
          Neither Plaintiff had enough contact with the visiting properties to allow
          those houses to be considered significant contributing factors. Lastly, a
          2010 ARC Environmental test of the exterior of the property found lead-
          based paint.

Thus, according to the Hamiltons, “there is sufficient direct and circumstantial evidence

to support the opinions of Dr. Blackwell-White and Dr. Simon.”

          The Circuit Court held a hearing on 10 August 2011. After hearing argument, the

Circuit Court stated, in pertinent part, on the record:

          I’m going to grant the motion. I’m, you know. Actually, I guess, eventually
          we’re going to get some more on a post-Dow[10] cases from the Appellate
          Courts. But basically, my understanding, this is not enough for the
          circumstantial evidence. . . . [T]he Court’s not convinced that there’s
          enough circumstantial evidence under Dow and I realized that that’s
          something that, you know, as a city, eventually we’ve got some
          clarification. But it’s my understanding that there’s sufficient, based upon
          the record here, that there’s sufficient evidence about so many other, not
          abstract sources, but very real sources, that it’s not sufficient. So for that
          reason, I will grant the motion.

On the next day, 11 August 2011, the Circuit Court entered an order granting the

Kirsons’ Motion for Summary Judgment “for the reasons stated on the record in open

court.”

          10
               Dow v. L & R Props., Inc., 144 Md. App. 67, 796 A.2d 139 (2002).

                                               -15-
       The Hamiltons appealed timely. On 30 April 2013, the Court of Special Appeals

issued an unreported opinion affirming the Circuit Court’s judgment granting summary

judgment. We granted a Writ of Certiorari, on the Hamiltons’ petition, 433 Md. 513, 72
A.2d 172 (2013), to consider the following questions:

       (1) Did the trial court err by refusing to allow plaintiffs’ expert witnesses to testify
       that the defendant’s property was a substantial contributing cause to plaintiffs’
       injurious lead exposure on the grounds that they did not sufficiently rule out other
       potential sources of lead exposure?

       (2) Did the trial court err by granting summary judgment for defendant on the
       grounds that there was insufficient evidence as to causation?

       (3) Is a Dow analysis applicable to a lead paint claim involving possible exposure
       at multiple properties?

              C. Consolidation

       We consolidate these cases for decision because they present a common, over-

arching inquiry—under what circumstances, if any, will circumstantial evidence alone of

the possible presence of lead-based paint inside a residential property be sufficient to

survive a defense motion for summary judgment challenging the sufficiency of proof of

the causation element of a negligence claim against the landlord. There is much recent

case law, particularly from the Court of Special Appeals, on the proof of lead paint

poisoning causation through circumstantial evidence. We aspire here to consider these

cases, add our judicial gloss to them, and resolve any inconsistencies.

       II.    STANDARD OF REVIEW

       In the present cases, the Circuit Court granted defense motions for summary

judgment, concluding that Plaintiffs failed to produce sufficient circumstantial evidence

                                             -16-
to make out a prima facie case regarding the causation element of a negligence claim.

The Circuit Court, in granting the motions for summary judgment, rejected implicitly or

explicitly Plaintiffs’ experts’ conclusions that the subject properties were a substantial

contributing source of Plaintiffs’ injuries.       The Court of Special Appeals, in its

unreported opinion in Hamilton, noted aptly the dual nature of the Circuit Court’s

decision:

       The Hamiltons argue that the circuit court erred in granting summary
       judgment because their experts had a sufficient factual basis for their
       opinions. They further assert that even without expert opinions, the other
       evidence was sufficient to show that the Bartlett address was a substantial
       contributing cause of their injuries. These two arguments go hand in hand
       because the evidence that the Hamiltons presented on causation was the
       same evidence the experts used to form their opinions. Thus, the circuit
       court decision contains two findings: 1) that the experts did not have a
       sufficient factual basis for their conclusions that the Bartlett property was a
       substantial contributing source, and 2) that the evidence the experts used as
       their factual basis was not enough to independently establish causation.

Hamilton v. Kirson, No. 1530, September Term, 2011, slip op. at 14-15 (Md. Ct. Spec.

App. April 30, 2013), cert. granted, 433 Md. 513, 72 A.2d 172 (2013). Regardless of the

dual nature of the decision, the case involved the grant of summary judgment and we

review it as such. 11

       11
         It appears that the Court of Special Appeals in Hamilton v. Dackman, 213 Md.
App. 589, 75 A.3d 327 (2013), and Taylor v. Fishkind, 207 Md. App. 121, 51 A.3d 743
(2012), reviewed the Circuit Court’s grant of motions for summary judgment on the
grounds of an insufficient basis for the expert’s testimony under two standards of review.
The intermediate court reviewed the trial court’s decisions regarding the sufficiency of
the experts’ opinions under an abuse of discretion standard, and the decisions regarding
the summary judgment without deference. That is not the standard to be employed.

                                                                              Continued…
                                            -17-
         A circuit court may grant a motion for summary judgment, entering judgment in

favor of the moving party, “if the motion and response show that there is no genuine

dispute as to any material fact and that the party in whose favor judgment is entered is

entitled to judgment as a matter of law.” Md. Rule 2-501(e). Maryland’s summary

Cont’d

       This Court recognizes that “in order to pass muster at a summary judgment
proceeding, the opponent must produce evidence that would be admissible at trial.”
Helinski v. Rosenberg, 90 Md. App. 158, 166, 600 A.2d 882, 886 rev'd, 328 Md. 664,
616 A.2d 866, rev’d on other grounds, Rosenberg v. Helinski, 328 Md. 664, 616 A.2d
866 (1992) (citing Gooch v. Maryland Mechanical Sys., Inc., 81 Md. App. 376, 396, 567
A.2d 954 (1990)); see also Gooch, 81 Md. App. at 396, 567 A.2d at 954 (“facts proffered
in opposition to the granting of a motion for summary judgment must be admissible in
evidence”) (citations omitted). Maryland Rule 5-702, which governs the admissibility of
expert testimony, provides:

         Expert testimony may be admitted, in the form of an opinion or otherwise,
         if the court determines that the testimony will assist the trier of fact to
         understand the evidence or to determine a fact in issue. In making that
         determination, the court shall determine (1) whether the witness is qualified
         as an expert by knowledge, skill, experience, training, or education, (2) the
         appropriateness of the expert testimony on the particular subject, and (3)
         whether a sufficient factual basis exists to support the expert
         testimony.

(Emphasis added.) Accordingly, where a circuit court grants a summary judgment
motion on the grounds that the plaintiff’s expert lacks a sufficient factual basis of
admissible facts and the admissible evidence (if any) is insufficient independently to
prove causation, the circuit court is making a decision on the admissibility of the expert’s
testimony as part of its summary judgment decision and, thus, is making a legal decision.
Such a decision is reviewed on appeal without deference, as the grant of all summary
judgment motions are. See, e.g., Giant Food, Inc. v. Booker, 152 Md. App. 166, 176-78,
831 A.2d 481, 486-87 (2003) (reviewing the denial of a motion for judgment and a
motion for judgment notwithstanding the verdict without deference, even though the
reasoning for the trial judge’s decision was based upon the admissibility of the expert
testimony due to an allegedly sufficient factual basis for concluding that accidental
exposure to Freon caused the plaintiff’s asthma).

                                             -18-
judgment rule makes clear that “a trial court determines issues of law; it makes rulings as

a matter of law, resolving no disputed issues of fact.” Beatty v. Trailmaster Products,

Inc., 330 Md. 726, 737, 625 A.2d 1005, 1011 (1993) (citing Heat & Power v. Air

Products, 320 Md. 584, 591, 578 A.2d 1202 (1990)). “In this regard, the standard for

appellate review of a trial court’s grant of a motion for summary judgment is simply

whether the trial court was legally correct,” id. (citations omitted), and is subject to no

deference. Tyler v. City of Coll. Park, 415 Md. 475, 498, 3 A.3d 421, 434 (2010)

(citations omitted).

      As such, in reviewing a grant of summary judgment, we review
      independently the record to determine whether the parties generated a
      dispute of material fact and, if not, whether the moving party was entitled to
      judgment as a matter of law. Charles County Comm'rs [v. Johnson], 393
      Md. [248,] 263, 900 A.2d [753,] 762 [(2006)]. We review the record in the
      light most favorable to the non-moving party and construe any reasonable
      inferences that may be drawn from the well-plead facts against the moving
      party. Conaway [v. Deane], 401 Md. [219,] 243, 932 A.2d [571,] 585
      [(2007)]; Charles County Comm'rs, 393 Md. at 263, 900 A.2d at 762

Id., 415 Md. at 498-99, 3 A.3d at 434.

       That our appellate review is premised on assumptions favoring the non-moving

party does not mean that the party opposing the motion for summary judgment prevails

necessarily. Rather,

       in order to defeat a motion for summary judgment, the opposing party must
       show that there is a genuine dispute as to a material fact by proffering facts
       which would be admissible in evidence. Consequently, mere general
       allegations which do not show facts in detail and with precision are
       insufficient to prevent summary judgment.
                                             ...
       [T]he mere existence of a scintilla of evidence in support of the plaintiffs'
       claim is insufficient to preclude the grant of summary judgment; there must
       be evidence upon which the jury could reasonably find for the plaintiff.

                                           -19-
       Anderson [v. Liberty Lobby, Inc.,] 477 U.S. [242,] 252, 106 S. Ct. [2505,]
       2512 [(1986)]. We recognized in Clea v. City of Baltimore, 312 Md. 662,
       678, 541 A.2d 1303 (1988), that while a court must resolve all inferences in
       favor of the party opposing summary judgment, “[t]hose inferences ... must
       be reasonable ones.” (Emphasis in original.) In that case, we quoted
       Professor Wright, as follows:
              “It is frequently said that summary judgment should not be
              granted if there is the ‘slightest doubt’ as to the facts. Such
              statements are a rather misleading gloss on a rule that speaks
              in terms of ‘genuine issue as to any material fact,’ and would,
              if taken literally, mean that there could hardly ever be a
              summary judgment, for at least a slight doubt can be
              developed as to practically all things human. A better
              formulation would be that the party opposing the motion is to
              be given the benefit of all reasonable doubts in determining
              whether a genuine issue exists.”
312 Md. at 678, 541 A.2d 1303, quoting C. Wright, The Law of Federal
       Courts § 99, at 666-667 (1983).

Beatty, 330 Md. at 737-39, 625 A.2d at 1011-12 (some internal citations omitted).

Furthermore, “it is a settled principle of Maryland appellate procedure that ordinarily an

appellate court will review a grant of summary judgment only upon the grounds relied

upon by the trial court.” Bishop v. State Farm, 360 Md. 225, 234, 757 A.2d 783, 787

(2000); see also Lovelace v. Anderson, 366 Md. 690, 695-96, 785 A.2d 726, 729 (2001).

       III.   DISCUSSION

       Generally, “[t]o state a claim for negligence a party must show ‘1) that the

defendant was under a duty to protect the plaintiff from injury, 2) that the defendant

breached that duty, 3) that the plaintiff suffered actual injury or loss, and 4) that the loss

or injury proximately resulted from the defendant’s breach of the duty.” Taylor v.

Fishkind, 207 Md. App. 121, 148, 51 A.3d 743, 759 (2012) (quoting Rosenblatt v. Exxon

Co., U.S.A., 335 Md. 58, 76, 642 A.2d 180 (1994)). Where an applicable statutory

                                            -20-
scheme is designed to protect a class of persons which includes the plaintiff, “the

defendant’s duty ordinarily ‘is prescribed by the statute’ or ordinance and . . . the

violation of the statute or ordinance is itself evidence of negligence.” Brooks v. Lewin

Realty III, Inc., 378 Md. 70, 78, 835 A.2d 616, 620 (2003) (quoting Brown v. Dermer,

357 Md. 344, 358-59, 744 A.2d 47, 55 (2000), overruled in part on other grounds by

Brooks, 378 Md. at 72, 835 A.2d at 617).

       This Court set out in Brooks the requirements for a plaintiff to make out a prima

facie showing in a statutory violation lead paint poisoning negligence action:

       [I]n order to make out a prima facie case in a negligence action, all that a
       plaintiff must show is: (a) the violation of a statute or ordinance designed to
       protect a specific class of persons which includes the plaintiff, and (b) that
       the violation proximately caused the injury complained of. Proximate
       cause is established by determining whether the plaintiff is within the class
       of persons sought to be protected, and the harm suffered is of a kind which
       the drafters intended the statute to prevent. . . . It is the existence of this
       cause and effect relationship that makes the violation of a statute prima
       facie evidence of negligence.
378 Md. at 79, 835 A.2d at 621 (internal quotation marks and citation omitted). Once a

plaintiff makes out a prima facie case in negligence, i.e., where he or she produces

“evidence that the violation of the statute proximately caused the plaintiff’s injury,” such

evidence is sufficient so as to “‘warrant the court in submitting the case to the jury on the

question of the [defendant’s] negligence.’” 12 Id. (alterations added in Brooks) (quoting

       12
         In several other jurisdictions, plaintiffs in lead paint poisoning negligence
actions are required additionally to adduce evidence that the tort defendant had
knowledge that he or she violated the statute. In Maryland, however, Brooks makes clear
that “once it is established that there was a statutory violation, the tort defendant’s

                                                                              Continued…
                                            -21-
Crunkilton v. Hook, 185 Md. 1, 4, 42 A.2d 517, 519 (1945)). Then, “[t]he trier of fact

must . . . evaluate whether the actions taken by the defendant were reasonable under all

the circumstances.” Id. (citations omitted). 13

         In the present cases, the plaintiffs relied upon violations of the City Housing

Code 14 to establish the landlord’s or homeowner’s prima facie negligence. In Brooks, we

summarized that, to establish a prima facie negligence case for lead-paint poisoning

based on violation of the Housing Code, a plaintiff must show that there was flaking,

loose, or peeling paint:

         In sum, the presence of flaking, loose, or peeling paint is a violation of the
         Housing Code. Brown v. Dermer, 357 Md. at 361, 744 A.2d at 56-57 (“To
         be a violation, all that must be shown is that there was flaking, loose or
         peeling paint”). As earlier pointed out, certain provisions of the Housing
         Code were clearly enacted to prevent lead poisoning in children. Therefore,
         the plaintiff . . . is in the class of people intended to be protected by the
         Housing Code, and his injury, lead poisoning, is the kind of injury intended
         to be prevented by the Code. This is all that the plaintiffs must show to
         establish a prima facie case sounding in negligence. Therefore, the notices
         of violation issued to Lewin Realty by the Department of Housing for

Cont’d

knowledge that he or she violated the statute is not part of the tort plaintiff’s burden of
proof. It is the violation of the statute or ordinance alone which is evidence of
negligence.” Brooks v. Lewin Realty III, Inc., 378 Md. 70, 80, 835 A.2d 616, 622 (2003)
(emphasis added).
         13
          In this sense, contrary to the contentions of the Respondents in Alston, prima
facie negligence differs from strict liability, which does not permit a defendant to explain
how his actions were reasonable.
         14
        Specifically, as noted earlier in this opinion, the plaintiffs relied on Housing
Code, Baltimore City Code (2000 Repl. Vol.), Art. 13, § 702, 703, & 706. See supra note
2.

                                             -22-
       unrelated properties were irrelevant and there should be a new trial as
       directed by the Court of Special Appeals.
378 Md. at 89, 835 A.2d at 627 (footnote omitted).

       Although peeling, chipping, or flaking paint (of any kind) constitutes a violation of

the Housing Code, such a Code violation permits merely an inference of prima facie

negligence on the part of the homeowner or landlord. Such an inference, however, does

not eliminate the requirement that the plaintiff prove that the landlord’s negligence

caused proximately the injury. As the Court of Special Appeals explained in Hamilton v.

Dackman, 213 Md. App. 589, 613, 75 A.3d 327, 340-41 (2013) (hereinafter, “Raymond

Hamilton”), “although the Court of Appeals suggested in Brooks that a statutory

violation may constitute a prima facie case of negligence, 378 Md. at 79, 835 A.2d 616,

that holding does not relieve a plaintiff of the obligation to establish causation.” More

specifically, the intermediate appellate court stated:

       Brooks eliminated notice of a lead-paint violation as one element of a
       negligence claim. 378 Md. at 72, 835 A.2d 616. The Court of Appeals
       explained that the plaintiffs did not have to provide notice and could submit
       their claim to the jury without proving that the landlord had notice “if the
       plaintiffs can establish a violation of the Housing Code which proximately
       caused [plaintiff's] injuries.” Id. at 81, 835 A.2d 616 (emphasis added).
       This meant, in Brooks, that where a child had been seen chewing repeatedly
       on a windowsill in a home that upon later inspection specifically was found
       to contain lead-based paint, id. at 73–74, 835 A.2d 616 (and whom the
       record did not reflect lived or visited any property other than the one that
       was the subject of the litigation), she could submit her case to the jury
       without having to show that the defendant had notice of the condition. Id. at
       72, 835 A.2d 616; see also Polakoff v. Turner, 385 Md. 467, 483, 869 A.2d
837 (2005) (permitting the plaintiff to submit her case to the jury if she
       “could establish a violation of the Code which proximately caused her
       injuries” (emphasis added)).

Raymond Hamilton, 213 Md. App. at 613, 75 A.3d at 341 (emphasis added in original).

                                             -23-
       In the present cases, because we elect to resolve the cases on the issue of

causation, we accept the premise that the subject properties were afflicted with peeling,

chipping, or flaking paint. Accepting such premise, the Hamiltons and the Alstons made

out prima facie cases that the defendants—the owners and/or landlords of the

residences—committed negligent acts in violation of the Housing Code.           Thus, we

address what quality or quantum of circumstantial evidence of causation is sufficient to

make out a prima facie showing for that element of the negligence case.

              A. Causation Analysis in Maryland Lead Paint Cases

       “It is fundamental that in a negligence action the plaintiff has the burden of

proving all the facts essential to constitute the cause of action.” Peterson v. Underwood,

258 Md. 9, 15, 264 A.2d 851, 854 (1970). One element of a negligence case is that the

defendant’s negligence was a proximate cause of the accident or injury.         See, e.g.,

Raymond Hamilton, 213 Md. App. at 613, 75 A.3d at 341. The inquiry here focuses on

“causation in fact,” one aspect of proximate cause, “concerned with the more

fundamental (and some have thought metaphysical) inquiry of whether defendant’s

conduct actually produced an injury.” Peterson, 258 Md. at 16-17, 264 A.2d at 855.

       We have recognized repeatedly that a plaintiff may prove causation in fact through

circumstantial evidence, as well as direct evidence or a mixture of the two. For example,

in Peterson, the Court stated:

       If lay testimony together with reasonable inferences does not directly show
       this causal relation (such as a witness's observing a brick hurled through a
       plate glass window) it may be shown in a number of other ways. The most
       familiar method today is through the opinion of the expert who states that,
       based on facts in evidence, X was the efficient cause of the injury. Such

                                          -24-
       opinion testimony is not always required, and the plaintiff produces legally
       sufficient proof to get to the jury once he shows it is more probable than not
       that defendant's act caused his injury. This does not mean plaintiff is
       required to exclude every other possible cause of the accident. But where
       plaintiff by his own evidence shows two or more equally likely causes of
       the injury, for only one of which defendant is responsible, plaintiff can not
       recover. The situation before us is somewhat analogous, except that instead
       of showing two evenly balanced probable causes, plaintiff has shown none.

       In the trial below plaintiff apparently relied on an inference that defendants'
       acts were the cause or proximate cause of the injury. An ‘inference’ is a
       deduction or conclusion which reason and common sense lead a jury to
       draw from the facts proved. United States v. Schneiderman, 106 F. Supp.
906, 928 (S. D. Cal. 1952), cf. 21 Words and Phrases, ‘inference’ (1960).
       This attempted reliance amounts to proof of causation by
       circumstantial rather than direct evidence. In accordance with the
       general rules stated above, this type of evidence is not inherently
       insufficient; all that is necessary is that it amount to a reasonable
       likelihood or probability rather than a possibility.
258 Md. at 17, 264 A.2d at 855 (emphasis added) (some internal citations omitted).

       When a plaintiff does not offer a direct explanation of the cause of the injury or

accident, a plaintiff is “compelled to rely entirely on the inference.” Peterson, 258 Md. at

18-19, 264 A.2d at 856. The validity of an inference “depends on commonly experienced

relationships of acts and forces,” id., 258 Md. at 18, 264 A.2d at 856, or “depends on

logical deduction from an established fact.” Id., 258 Md. at 19, 264 A.2d at 856. Certain

sets of facts may make an inference less valid than other sets of facts. See, e.g., id., 258

Md. at 21, 264 A.2d at 857 (concluding that the passage of time between the negligent act

and the injury rendered the inference of causation illogical and thus concluded that the

trial court’s granting of summary judgment was proper).            The conclusion that an

inference is not valid due to a lack of supporting facts or an articulable logical

relationship does not mean that we place greater weight on direct evidence than on

                                            -25-
circumstantial evidence.    Rather, it means that we require inferences to be sound

logically, and we refuse to allow a jury of laymen to engage in “‘guesswork, speculation

and conjecture.’” Id., 258 Md. at 21, 264 A.2d at 857 (quoting Wilhelm v. State Traffic

Safety Comm., 230 Md. 91, 101, 185 A.2d 715, 719 (1962)).

       In the context of lead paint cases, this Court’s next most recent decision on

causation is Ross v. Housing Authority of Baltimore City, 430 Md. 648, 63 A.3d 1 (2013).

In Ross, the Court recognized aptly that, in the typical lead-paint case, 15 the theory of

causation has multiple analytical layers:

        The theory of causation presented in this case can be conceived of as a
       series of links: (1) the link between the defendant's property and the
       plaintiff's exposure to lead; (2) the link between specific exposure to lead
       and the elevated blood lead levels, and (3) the link between those blood
       lead levels and the injuries allegedly suffered by the plaintiff. To be a
       substantial factor in causing Ms. Ross' alleged injuries, the Payson Street
       home must have been a source of Ms. Ross' exposure to lead, that exposure
       must have contributed to the elevated blood lead levels, and the associated
       increase in blood lead levels must have been substantial enough to
       contribute to her injuries.

Ross, 430 Md. at 668, 63 A.3d at 12-13 (emphasis added) (footnote omitted). In the

present cases, we are concerned with the first link. To prove this link, circumstantial

evidence may be used, “so long as it creates ‘a reasonable likelihood or probability rather

       15
         In reiterating this multi-level causation approach, we repeat also the admonition
in Ross: “We do not mean to rule out the possibility of other ways that a plaintiff might
demonstrate that lead exposure is a substantial factor in a resulting harm to an
individual.” 430 Md. at 668 n.20, 63 A.3d at 13 n.20. In these consolidated cases,
however, both sets of plaintiffs relied on the same causation theory as in Ross. Thus, we
do not dwell on hypotheticals beyond those deemed necessary to clarify or illuminate the
law.

                                            -26-
than a possibility’ supporting a ‘rational inference of causation,’ and is not ‘wholly

speculative.’” West, 212 Md. App. at 170-71, 66 A.3d at 1150 (citations omitted). The

Hamiltons’ and Alstons’ cases hinge on that fine distinction between circumstantial

evidence that amounts to a reasonable likelihood or probability and circumstantial

evidence that amounts only to a possibility and speculation.

       To connect the dots between a defendant's property and a plaintiff's exposure to

lead, the plaintiff must tender facts admissible in evidence that, if believed, establish two

separate inferences: (1) that the property contained lead-based paint, and (2) that the lead-

based paint at the subject property was a substantial contributor to the victim’s exposure

to lead. At times, these separate inferences may be drawn from the same set of facts, but

parties would do well to remember that these inferences are separate and often will

require different evidentiary support.

       In an effort to contribute to clarification of any confusion, we consider first Dow v.

L & R Properties Inc., 144 Md. App. 67, 796 A.2d 139 (2002), which represents a

scenario where multiple inferences seek to draw succor from the same factual reservoir:

       In [Dow], a child and her mother sued their landlord for injuries the child
       allegedly suffered as a result of ingesting lead paint in their home. The
       discovery materials and an affidavit of the mother indicated that the home
       had been built prior to 1950 and thus likely had lead paint, that there was
       chipping and peeling paint in areas where the child played and that the
       child placed paint chips in her mouth, that the child spent most of her time
       in the home while she lived there and did not have contact with other
       sources of lead during that period, and that the child developed lead
       poisoning.

       The landlord in Dow moved for summary judgment, arguing that (1) the
       plaintiff had not identified an expert who would testify that there was lead
       paint on the premises and (2) there was no other direct evidence that the

                                            -27-
       paint contained lead. As a result, the landlord argued, there was insufficient
       evidence to prove causation and the landlord was entitled to judgment as a
       matter of law. The Court of Special Appeals rejected that argument and
       concluded that the circumstantial evidence was sufficient to generate a
       genuine issue of material fact and thus defeat the landlord's motion for
       summary judgment. 144 Md. App. at 74–75, 796 A.2d 139. The court
       reasoned that it was not necessary for the plaintiff to prove causation by
       direct evidence; circumstantial evidence that “amounts to a reasonable
       likelihood or probability rather than a possibility” would suffice. Id.
       (quoting Peterson v. Underwood, 258 Md. 9, 17, 264 A.2d 851 (1970)).
       The court held that evidence offered by the plaintiff in opposition to the
       motion, if believed by the fact-finder, could support an inference that the
       property was the only possible source of the child's lead poisoning. Id. at
       76, 796 A.2d 139.

Ross, 430 Md. at 669-70, 63 A.3d at 13 (summarizing Dow).

       In sum, the facts in Dow showed that (1) the child victim spent most of her time at

the subject property where she lived and did not have contact with other possible sources

of lead during the relevant period; (2) the child was observed ingesting regularly flaking

or chipping paint at that property; (3) the child played frequently in the area of the flaking

or chipping paint; and (4) the child had high blood lead levels during that time period,

i.e., developed lead poisoning. The court concluded that, under those circumstances,

there was more than a mere possibility that the house where the child resided and spent

most of her time was the only possible source of the lead exposure. As such, because the

child spent almost all of her time at the house, the court concluded additionally that it was

more than a mere possibility that the house contained lead-based paint. Even though

there was no direct evidence of lead at that property, i.e., no scientific testing, it was

reasonable to infer that there had to be lead at that property because the child would not

have suffered otherwise from lead poisoning. In that sense, the plaintiff eliminated all

                                            -28-
other possible sources of lead poisoning in order to make reasonable and probable those

conclusions. Thus, the court drew two necessary, separate inferences on the basis of the

same set of facts.

       In a very instructive case, Ross, this Court found, in reviewing the grant of

summary judgment in favor of defendants, that a reasonable inference would be “that the

lead investigation reports for the [plaintiffs’] home accurately identified lead on the

property.” 430 Md. at 670, 63 A.3d at 14. The Ross Court detailed the facts supporting

this inference:

       The 1992 inspection returned positive results for exterior lead as well as
       “surface dust” on the interior. The 1994 inspection again indicated the
       presence of lead on exterior walls. The only direct evidence of an indoor
       source of lead was the 2009 ARC [E]nvironmental survey that indicated the
       presence of lead on an interior stair riser, though it is not indicated in the
       record whether that location was tested earlier or whether it was in a
       deteriorating condition in the early 1990s.

Ross, 430 Md. at 671 n.23, 63 A.3d at 14 n.23. 16 As such, Ross and Dow are examples of

cases with sufficient circumstantial evidence for the drawing of separate and reasonable

inferences of the presence of lead at the subject property.

       16
          In Ross, the Circuit Court refused to let the case go to the fact-finder in the
absence of an expert’s admissible testimony. We held, however, that an expert was not
necessary to connect the dots between the lead on the property and the child’s exposure
to lead and, therefore, remanded the case to the Circuit Court. We cautioned:

       [I]t may well be that, once the parties have marshaled the evidence without
       the expert opinion on source, it is clear which facts are disputed and which
       are not, and the limits of the inferences in plaintiff’s favor are evident,
       summary judgment might still be warranted.

                                                                             Continued…
                                            -29-
         The present cases, in contrast, lack the same or similar quality of circumstantial

evidence undergirding the desired inferences. Despite this difference, Plaintiffs here

cling to the same theory of causation advanced by the plaintiffs in Dow. Specifically,

Plaintiffs ask this Court to permit a fact-finder to draw multiple inferences from a

singular group of facts, even though Plaintiffs failed to exclude other potential sources of

lead in these cases. Moreover, Plaintiffs declined to use seemingly available judicial

methods 17 for testing the interior of the houses. 18 We have yet to address this scenario,

Cont’d

Ross, 430 Md. at 671, 63 A.3d at 14.
         17
           For example, where a defendant owns still the subject property, Md. Rule 2-
422(a) supplies a mechanism for the inspection and testing of the property for the
presence of lead-based paint, providing in pertinent part: “[a]ny party may serve one or
more requests to any other party . . . (2) to permit entry upon designated land or other
property in the possession or control of the party upon whom the request is served for the
purpose of inspection, measuring, surveying, photographing, testing, or sampling the
property . . . .” See also Butler v. S & S P’ship, 435 Md. 635, 645-49, 80 A.3d 298, 305-
07 (2013) (discussing the application of this Rule in-depth).
        In contrast, though, in those lead-paint cases in which the defendant is a former
owner and a different person or entity owns the subject property at the time of the
litigation, such as the present cases, the plaintiffs may not avail themselves of Md. Rule
2-422. See Webb v. Joyce Real Estate, Inc., 108 Md. App. 512, 517 n.2, 672 A.2d 660,
662 n.2 (1996) (concluding that Md. Rule 2-422 did not authorize entry onto property
owned by a nonparty because, under Rule 2-422, “nonparties may not be compelled to
submit to an inspection of their property”). The Court of Special Appeals made clear in
Stokes v. 835 N. Washington Street, LLC, 141 Md. App. 214, 784 A.2d 1142 (2001),
however, that a plaintiff so situated may have other judicial avenues through which he or
she may seek testing of the interior of a house owned by a non-party.
        In Stokes, the defendant was the former owner of the subject property. The current
owner of that property refused the plaintiffs’ request for access to that property in order
to conduct a test for the presence of lead-based paint. The plaintiffs filed an action
against the current owner, seeking an order for entry upon the property to conduct a

                                                                             Continued…
                                            -30-
but the Court of Special Appeals addressed it in West v. Rochkind, 212 Md. App. 164, 66
A.3d 1145 (2013), and Hamilton v. Dackman, 213 Md. App. 589, 75 A.3d 327 (2013).

We consider those cases now.

Cont’d

“noninvasive and nondestructive test” on the paint in the interior of the residence. The
Circuit Court denied that motion. Plaintiffs appealed.
        The Court of Special Appeals recognized that the plaintiffs were not permitted
under Md. Rule 2-422 to enter onto the property owned by a non-party, and that no other
Maryland rule provided explicitly for the circuit court to grant such relief. Despite the
absence of a rule, however, the court held that the plaintiffs were permitted to request
such relief from the circuit court, and “the circuit courts have the power to order
inspection of a non-party’s property on a case-by-case basis through the equitable bill of
discovery.” Stokes, 141 Md. App. at 221, 784 A.2d at 1146-47. The intermediate
appellate court reasoned that “the absence of a rule expressly authorizing an inspection
does not preclude the circuit court from granting that relief when it is in the interest of
justice to do so.” Id., 141 Md. App. at 222, 784 A.2d at 1147-48.
         18
          We recognize that practical difficulties may preclude a plaintiff from testing the
interior of a dwelling, particularly if the home has been razed since the victim ceased
living there. In the present cases, however, we have no evidence of any grave difficulty
that would have precluded Plaintiffs from obtaining testing. In Alston, there is no
evidence that Plaintiffs made any attempt to test the exterior or the interior of the home
alleged to be a source of Plaintiff’s injuries. In Hamilton, Plaintiffs hired a lead
investigator to test the relevant subject property. When the investigator arrived at the
home, the current resident permitted the investigator to test only the exterior of the house,
but would not permit him to enter for testing. Even in Hamilton, however, there is no
evidence in the record that Plaintiffs attempted to use judicial devices to obtain testing of
the interior.
        We note the lack of direct evidence not because it is required per se. We note it in
response to the Hamiltons’ and the Alstons’ arguments that to require more evidence than
Plaintiffs presented in these cases is an “insurmountable burden” for lead-paint plaintiffs
generally. Without evidence that Plaintiffs exhausted reasonable avenues to gather direct
or circumstantial evidence of the presence of lead paint, we find it impossible to conclude
that this standard is “insurmountable.” Moreover, this Court acknowledged in many
negligence cases that some cases simply do not have enough information to hold the
defendant to trial. In this regard, an “insurmountable burden” is appropriate for cases that
would leave the jury to guesswork and speculation.

                                            -31-
      In West, the plaintiff alleged that he sustained injuries from ingesting chipping and

flaking paint while living with his grandmother in a property owned and leased out by the

defendants. West’s negligence claim was based on circumstantial evidence because the

property, since razed, had not been the subject of lead testing. The defendants filed a

motion for summary judgment, which the Circuit Court for Baltimore City granted,

concluding that West failed to make out a prima facie negligence case because, unlike in

Dow, West’s mother stated during deposition that West either resided or spent substantial

amounts of time at a variety of houses during the first six years of his life, during which

he experienced lead poisoning. The Circuit Court reasoned that, in light of West’s

“uncertain residential history and the lack of any direct evidence that [the subject

property owned by the defendants] ever contained lead paint, [West] could not point to

[the subject property] as the source of his lead poisoning.” West, 212 Md. App. at 166,

66 A.3d at 1146.

       On appeal, the Court of Special Appeals agreed. The intermediate appellate court

acknowledged that “[a] lead paint plaintiff may, of course, establish a prima facie case of

negligence based solely on circumstantial evidence.” West, 212 Md. App. at 175, 66

A.3d at 1151. For example, the court cited Dow, in which there was also no direct

evidence that lead paint was present at the subject property. The court distinguished

Dow, however, on the grounds that “the process of elimination showed ineluctably that

[the subject property] had to have been (not could have been, but had to have been), a

place containing lead paint.” Id., 212 Md. at 172, 66 A.3d at 1149. The West court

explained:

                                           -32-
       The evidence showed indisputably that the only place where she could have
       been exposed to lead paint was at [the subject property]. There was only
       one possible cause for the undisputed effect [because deposition testimony
       indicated that the plaintiff did not live or spend substantial time at any other
       property]. By process of elimination, there was no other possible source of
       exposure. That, we held, constituted solid circumstantial evidence that the
       house contained lead paint . . . .

Id., 212 Md. at 172, 66 A.3d at 1149-50.

       That the facts in Dow permitted the court to derive two analytic steps from a

singular set of facts, the West court cautioned, “should not obscure the fact that there was

still involved a two-step analytic process, and that what may be said about one step in

that analytic process does not necessarily apply to the other step.” West, 212 Md. App. at

173, 66 A.3d at 1150. Reiterating, the necessary two-steps are (1) the plaintiff must show

first that the subject property had lead-based paint, and (2) then the plaintiff must show

that his or her exposure at the subject property “was an effective cause of his lead

poisoning.” Id. According to the West court, the second step, “[t]he proof of ultimate

causation[,] does not demand exclusivity.” Id. The first step, the proof that the subject

property had lead paint, however, does demand exclusivity. Id.

       Based on the distinction between the proof required to satisfy these two steps, the

West court concluded that “where no direct evidence that [the subject property] even

contained lead paint, [West] may only rely on that critical fact, as a necessary part of his

circumstantial evidence, if he can show by the process of elimination that [the subject

property] was the only possible cause for the critical effect of lead poisoning.” West, 212
Md. App. at 175, 66 A.3d at 1151. In other words, “[the court] may only infer the

existence of lead paint at [the subject property] from [West]’s condition if lead paint at

                                            -33-
[the subject property] is shown to have been the only possible explanation for [West]’s

condition.”   Id.    To expound on this “subtle,” “critical” distinction, the West court

explained further:

       The distinction that Dominique [the victim] fails to grasp is a subtle one; it
       is nonetheless a critical one. In Dominique's forensic syllogism, his
       conclusion of ultimate liability does not, to be sure, depend upon the
       exclusivity of 1814 Lorman Street as a source of his lead poisoning.
       Lorman Street could readily share liability with two or three other places of
       exposure. That, however, is not the point. Before even getting to a
       syllogism's conclusion, one must first establish the premises out of which
       the conclusion arises. A necessary premise in this case is that there was,
       indeed, lead paint at 1814 Lorman Street. It is with respect to that
       antecedent premise, not with respect to the ultimate conclusion, that the
       lack of exclusivity is Dominique's Waterloo. It is the teaching of Dow that,
       even in the absence of direct proof, the presence of lead paint at a particular
       site can be inferred by the process of elimination, but only if we have 1) the
       effect of lead poisoning in the plaintiff and 2) the fact that the site in
       question was the exclusive possible source of the plaintiff's lead paint
       exposure. It was the truth of that premise that Dominique failed to establish
       in this case, not the validity of the conclusion proceeding from the
       premises. Exclusivity was not required at B. It was required at A, before
       one even gets to B.

West, 212 Md. App. at 175-76, 66 A.3d at 1151-52.

       We agree with the West court’s analysis for application to those cases where a

plaintiff relies on a Dow theory of causation. Under a Dow theory of causation, a

plaintiff must rule out other reasonably probable sources of lead exposure in order to

prove that it is probable that the subject property contained lead-based paint. Where the

plaintiff fails to rule out other reasonably probable sources, the necessary inferences for a

Dow theory of causation cannot be drawn with sufficient validity to allow the claim to

survive summary judgment. See also Taylor, 207 Md. App. at 136, 150, 51 A.3d at 752,

760-61 (concluding that the trial court granted aptly the defense motion for summary

                                            -34-
judgment on the grounds that “[t]he evidence in this case does not come close to the kind

of circumstantial evidence that the Court found sufficient in Dow and that . . . it’s not

simply the age of the house and even the peeling”). That certain facts are missing to

establish a Dow theory of causation, however, does not mean that the lead-poisoned

plaintiff has no way to prove circumstantially a prima facie negligence case. To the

extent that West suggests that a lead-paint plaintiff must exclude all other sources of lead

exposure in every instance of circumstantial proof, we do not agree necessarily with that

conclusion.

       A lead-paint poisoned plaintiff may prove circumstantially that the subject

property contained lead-based paint in a number of ways. As discussed above, if a

plaintiff is able to exclude other reasonably probable sources of lead, such as in Dow,

then the plaintiff presents a prima facie case. By way of another example, consider this

illustration representing a traditional short series of row houses in Baltimore:
                                                     Row house “B” =
                                                     subject property that a plaintiff
                                                     wishes to prove contains lead-based
                                                     paint.

                                                     Row house “A” and “C” =
                                                     properties that tested positive
                                                     previously for lead on the interior

                                                     Row house “D” =
                                                     unknown if property contains lead
In this hypothetical, row house “B” is the subject property (designated with the “X”) that

a plaintiff hopes to prove, through circumstantial evidence, contains lead-based paint.

Perhaps the row house was razed, however, and direct testing is impossible at the time of

                                            -35-
the litigation. There exists, however, evidence that these four row houses were built at

the same time in the 1920’s and that they were owned as a group by a series of persons or

entities through the 1950’s. Moreover, the City’s records reveal that row houses “A” and

“C” (designated with stripes) tested positive previously for lead paint on the interior of

the houses. Thus, in this hypothetical (at least in the absence of evidence of lead

abatement measures), the plaintiff is able to present circumstantial evidence from which a

jury could infer reasonably that the subject property contained lead-based paint—without

having to exclude all other sources of potential exposure to lead-paint poisoning. 19

       Where a plaintiff who does not produce evidence to support another theory of

causation and, instead, relies on a causation theory similar to that espoused in Dow, the

validity of the necessary inference is limited to those circumstances where the plaintiff is

able also to exclude other reasonably probable sources of lead exposure.

                B. Bridging the Inference Link with Expert Testimony

       Plaintiffs in the present cases argue that their experts’ testimony bridged any

evidentiary gap in their circumstantial proof. Specifically, their experts opined that the

subject properties were probably a substantial contributor to Plaintiffs’ injuries.

       The Court of Special Appeals addressed a similar contention in Raymond

Hamilton, 213 Md. App. 589, 75 A.3d 327. In that case, the plaintiff lived at three leased

dwellings: (1) a house on Gilmor Street from birth until 1993; (2) a house on Harlem

Avenue from 1993 to 1995; and (3) a house on Fulton Avenue from 1995 to 1999. None

       19
            This illustration only forges one of the Ross links.

                                               -36-
of those houses, however, was the subject of Raymond’s claim of lead poisoning, but

rather a property on Appleton Street, the home of the plaintiff’s father, where the plaintiff

visited often and stayed sometimes overnight.

       During discovery in Raymond Hamilton, the plaintiff presented a report of the

results of a technician’s lead testing on eight exterior surfaces of the Appleton property.

Of the eight areas tested, only one—the rear exterior door transom—tested positive for

the presence of lead paint. Additionally, the plaintiff identified two experts: Dr. Robert

K. Simon, Ph.D., a chemist and industrial hygienist (the same expert as appears in

Hamilton v. Kirson), and Dr. Jacalyn Blackwell-White, M.D., a board-certified

pediatrician (the same expert as appears in Ross, 430 Md. at 656, 63 A.3d at 5, as well as

in Hamilton v. Kirson). The Court of Special Appeals described Dr. Simon’s opinion as:

        [Dr. Simon] opined that the Appleton Street property was a source of [the
       plaintiff’s] exposure to lead-based paint. He assumed from the age of the
       Appleton Street property that it contained lead-based paint (invoking Md.
       Code Regs. 26.16.01.03(A) (2013)).[20] When asked to describe the basis
       for his opinion that the Appleton Street property contained lead-based
       paint, Dr. Simon admitted that he assumed the presence of lead both there
       and at the Harlem Avenue property from the properties’ age . . . .

Raymond Hamilton, 213 Md. App. at 595-96, 75 A.3d at 330.

       Dr. Blackwell-White “opined that the Appleton Street, Harlem Avenue, and

Fulton Avenue properties all were sources of lead-based paint and that [the plaintiff]’s

       20
           The regulation provides: “The presence of a lead-containing substance is
presumed in any residential building constructed before 1950 unless a person determines
that all painted surfaces are lead-free in accordance with § B of this regulation.” Md.
Code Regs. 26.16.01.03(A) (2013).

                                            -37-
injuries were caused by exposure at the sites . . . .” Id., 213 Md. App. at 597, 75 A.3d at

331. She explained, in part: “Both properties [the Appleton Street and Harlem Avenue

properties] were old and in the absence of physical lead assessment information, are

presumed to have contained lead based paint.” Id. During a deposition of Dr. Blackwell-

White, defense counsel asked repeatedly whether Dr. Blackwell-White could rule out the

other properties as a contributing source. Dr. Blackwell-White replied that she could not.

When she was asked what was the basis of her opinion, she stated: “That [the Harlem

Avenue property] too, was an older property in disrepair. And it was the property of

residence when the elevated lead levels were found.” Id., 213 Md. App. at 600, 75 A.3d

at 333.

          Dackman moved for summary judgment, arguing (1) that the plaintiff “had failed

to provide either direct or circumstantial evidence demonstrating the presence of lead at

the Appleton Street property during the relevant time period, and (2) that he could not

rule out other properties as potential sources.” Id. In particular, “Dackman also claimed

that because Raymond’s experts admitted they were unable to rule out other sources of

lead exposure or other properties as containing lead, they lacked an adequate factual basis

to conclude that the Appleton Street property was the source of his lead exposure.” Id.,

213 Md. App. at 600-01, 75 A.3d at 333 (emphasis in original).

          The plaintiff retorted that there was abundant evidence:

          He argued that the Arc Report’s single positive test demonstrated he was
          exposed to lead at the Appleton Street property. And he claimed that this
          evidence coupled with the testimony of his experts established a prima
          facie case that the Appleton Street property was a ‘substantial contributing
          factor’ to his injuries because he was required only to show that ‘he was,

                                              -38-
       more likely than not, exposed to lead paint at a given subject property.’ He
       argued that he was not required to prove only a single source of lead
       exposure or a single cause of his injuries.

Id., 213 Md. App. at 601, 75 A.3d at 333. The Circuit Court granted the defense motion

for summary judgment, holding that the plaintiff “had not produced evidence sufficient to

establish a prima facie case of lead exposure at the one property at issue here, and the

court declined to allow [the plaintiff’s expert] to fill the causal gaps.” Id., 213 Md. App.

at 591-92, 75 A.3d at 328.

       On appeal, the Court of Special Appeals stated that “an expert cannot transform

thin evidence or assumptions into viable causal connections simply by labeling them an

expert opinion.” Id., 213 Md. App. at 608, 75 A.3d at 338; see also Taylor v. Fishkind,

207 Md. App. 121, 142, 51 A.3d 743, 756 (2012) (“‘[a]n expert’s opinion testimony must

be based on [an] adequate factual basis so that it does not amount to conjecture,

speculation, or incompetent evidence.’”) (quoting Giant Food, Inc. v. Booker, 152 Md.

App. 166, 182-83, 831 A.2d 481 (2003) (alterations in original)). Moreover, the court

stated that Maryland courts “have for some time required more of a plaintiff than simply

a showing that he lived in an old house in an area where lead-based paint historically was

present.” Raymond Hamilton, 213 Md. App. at 612, 75 A.3d at 340; see also id. (“‘[T]he

mere fact that most old houses in Baltimore have lead-based paint does not mean that a

particular old Baltimore house has a similar deficiency.’”) (quoting Davis v. Goodman,

                                           -39-
117 Md. App. 378, 393, 700 A.2d 798, 805 (1997)). 21 Thus, the court emphasized that “a

plaintiff bears the burden to establish the presence of lead in the child’s environment, and

cannot just assume it merely from the age or location of the house.” Id. In applying

those principles to the experts’ opinions in Raymond Hamilton, the Court of Special

Appeals concluded that neither of the experts possessed the qualifications necessary, nor

the factual basis, to render an opinion as to the source of the lead that the child ingested.

Moreover, the court reasoned that, similar to Ross, because the expert “reached a

conclusion as to the source notwithstanding the presence of other potential sources of

lead, and as such her opinion ‘was as likely to confuse as to assist a jury.’” Id. (quoting

Ross, 430 Md. at 664, 63 A.3d at 10).

       The intermediate appellate court held that, without the experts’ testimonies, “the

evidence proffered here would have allowed a jury at most to find a possibility that the

circumstantially-established lead exposure at the Appleton Street property was a source

of [the plaintiff’s] alleged injuries. That is not enough: a plaintiff must establish . . . a

probability that a property exposed him or her to injury-causing lead paint.” Id., 213 Md.

       21
          These statements in Raymond Hamilton and Davis—that the presence of lead
paint cannot be determined based on the general area of an “old” house—were in
response to the argument that the presence of lead paint should be presumed in all houses
built in Baltimore City during certain time periods, in light of reports that indicate a high
percentage of similarly situated houses contained lead paint. The court concluded aptly
that the inference had an insufficient factual basis. In contrast, the hypothetical we
presented earlier in this opinion at 35-36 differs in the type of factual basis upon which
the inferences rely.

                                            -40-
App. at 605, 75 A.3d at 336 (citing Ross, 430 Md. at 664, 63 A.3d at 10) (emphasis in

original).

       In sum, Dow does not define the only set of circumstantial facts that may satisfy a

plaintiff’s burden to establish a prima facie negligence case for lead paint poisoning. The

pertinent question to be asked is whether the particular circumstantial evidence permits

an inference or inferences of the desired ultimate fact or facts as a “reasonable likelihood

or probability,” and not a mere “possibility.” To the extent that the Court of Special

Appeals’s opinions discussed in this opinion suggest that the only way to prove a prima

facie negligence case circumstantially is to eliminate every other reasonable possibility as

an alternative source, we do not agree with the exclusivity of such a conclusion. With

this understanding and these principles in mind, we shall apply them to the present cases.

              C. Analysis

                     i. Hamilton

       There was no direct evidence adduced of lead-based paint in the interior of 754

Bartlett Avenue. Moreover, there was no evidence, as there was in Dow, that the children

spent substantially all of their time in one house, the subject property, such that the

Circuit Court could conclude that a fact-finder could be persuaded that there was a

reasonable probability that the subject property contained lead-based paint. The Court of

Special Appeals, in an unreported opinion, emphasized that, in order to prove a prima

facie case, “the evidence . . . would have had to provide the experts with enough

information to rule out other possible sources of lead exposure to create the

circumstantial evidence that the Hamiltons were exposed to lead at the Bartlett house.”

                                           -41-
Hamilton, slip op. at 21. The intermediate appellate court held that the evidence in the

Hamiltons’ case did not do so:

       Here, the Hamiltons presented an Arc report regarding exterior surfaces, the
       mother’s statements that the boys put paint chips in their mouths at the
       Bartlett house, the elevated blood levels, and the age of the house. This
       evidence suggests, but is not sufficient to create a genuine dispute as to
       whether the Bartlett address contained lead paint unless the Bartlett
       property was the only place where the Hamiltons could have been exposed
       to lead paint. . . . Dr. Blackwell-White and Dr. Simon conceded that . . .
       two [other visiting] properties could not be ruled out as potential sources
       because there was some information that suggested they contained lead,
       and Dr. Simon specifically stated that the time spent at those houses
       increased the possibility of lead exposure.

Id. at 20-21. In so holding, the court acknowledged that “more than one home can be a

substantial contributing source of lead and therefore, more than one landowner could be

liable for a child’s lead poisoning.” Id. at 21. The court went on, though, stating:

       However, the underlying assumption in that statement is that both houses
       had the potential to cause injury because they actually contained lead.
       Based on our case law, to even enter the realm of ‘substantial contributing
       source,’ a house has to be shown to have had lead-based paint - - almost
       invariably in the interior of the building. Without direct evidence that
       the Bartlett house contained lead, the Hamiltons’ only option was to
       eliminate other sources of lead poisoning, not to establish that the only
       place responsible for the Hamiltons’ lead poisoning was the Bartlett
       house, but to show that the Bartlett house contained lead. However,
       neither of Hamiltons’ experts could eliminate the other potential sources of
       lead. In fact, they were provided with little information on those other
       potential sources.

Id. at 21-22 (emphasis added).

       The Court of Special Appeals recognized aptly the multi-layered nature of the

causation analysis in circumstantial evidence cases. The court stated that the Hamiltons

were not required “to establish that the only place responsible for the Hamiltons’ lead

                                            -42-
poisoning was the Bartlett house, but [were required] to show that the Bartlett house

contained lead.” Id. at 21. We depart from the reasoning of the intermediate appellate

court, however, that, without direct evidence, “the Hamiltons’ only option was to

eliminate other sources of lead poisoning.” Id. As we discussed above at 35-36 in our

hypothetical of the block of row houses, there may be other ways that an injured plaintiff

may establish that it was probable that the interior of a subject house contained lead.

Accordingly, the sole concern should not be that the Hamiltons’ experts were provided

with little information on other potential sources of lead exposure. Rather, the concern

should be that the Hamiltons’ experts reached the conclusion that the house contained

lead-based paint on a presumption that houses built during a certain time period contain

typically lead-based paint. Such a factual basis is insufficient for an expert to reach the

conclusion that the interior of a specific property contained lead-based paint during the

relevant time period.

                    ii. Alston

       In Alston, at the end of the motions hearing, the Circuit Court concluded that the

defense motion for summary judgment should not be granted on the basis of uncertainty

over where Plaintiffs lived, even though there was very little evidence and that which was

adduced was “extremely sketchy in this case.” Instead, the judge granted the defendant’s

motion for summary judgment on the basis of a failure to offer sufficient proof of

causation linking the plaintiff’s elevated blood lead levels and the specific conditions of

the subject properties. The Circuit Court’s reasoning is important to our (and its) analysis

and, thus, we expound further.

                                           -43-
       The Circuit Court accepted that Plaintiffs showed that the subject properties had

“deteriorating paint” and that, at least for purposes of the summary judgment motion,

Plaintiffs “exhibited elevated blood lead levels at around the time that they say they were

living in these properties.” Moreover, the Circuit Court acknowledged correctly that

generally Plaintiffs could prove a causal link “indirectly by circumstantial means.” The

Circuit Court concluded, however, that the plaintiffs failed to forge the first inferential

link because:

       I think the essential logical ingredient that must be present in order for Dow
       or a theory like Dow to apply is that logically there must be a -- a very
       strong conclusion that the lead [poisoning] that the plaintiffs were
       experiencing had to come from this source because there is no other
       logical source that is available.

(Emphasis added.) The Circuit Court stated on the record that “there may be a number

of ways that could be done” and then provided several examples:

       I’ve suggested one of them would be if there were visitation properties, that
       there is some evidence that tends to exclude those. There might be
       evidence that the paint wasn’t deteriorating in those. There might be
       evidence that they were built after a period when lead paint was likely
       present. [sic] There might be evidence that the visits were very short, were
       supervised closely and the children didn’t ingest paint. There may be a
       number of bases that might be advanced by plaintiff.

The problem, the Circuit Court stated, was that “you simply have two wide open possible

properties at the same time, either of which could have been the source of the lead that is

alleged. And that is insufficient to establish the prima facie case that the plaintiff would

have to show on negligence.”

       On appeal, the Alstons argue that this analysis was defective.         We disagree.

Plaintiffs bear the initial burden of proving circumstantially a prima facie negligence

                                           -44-
case. Part of that burden is to advance a viable theory of causation. In the Alstons’ case,

they argued a Dow theory of causation, but, as the Circuit Court noted, the Alstons failed

to produce the quantum or quality of evidence noted in Dow, namely, they failed to

eliminate other reasonably possible identified sources of lead exposure. Thus, the Circuit

Court’s comparison of the Alstons’ case to Dow was appropriate and its ultimate

conclusion that the Alstons’ failed to meet their initial burden was correct.

                                              JUDGMENTS OF THE COURT OF
                                              SPECIAL    APPEALS    AFFIRMED.
                                              COSTS TO BE PAID BY PETITIONERS
                                              IN THEIR RESPECTIVE APPEALS.

                                            -45-