REPORTED 

IN THE COURT OF SPECIAL APPEALS 

OF MARYLAND 

 

No. 2126 

September Term, 2014 

______________________________________ 

ROBERT AMOS PATTERSON

v. 

STATE OF MARYLAND

______________________________________ 

 Eyler, Deborah S.,

Arthur,

Kenney, James A., III

 (Senior Judge, Specially Assigned), 

JJ.

______________________________________ 

Opinion by Arthur, J.

______________________________________ 

 

 Filed: September 27, 2016 
Robert Amos Patterson, an inmate representing himself, appeals from the denial of 

a petition for writ of actual innocence, in which he challenged his 1993 convictions for 

first-degree murder and related handgun offenses. He raises a single question, which we

have rephrased as follows: Did the circuit court abuse its discretion in denying the 

petition for writ of actual innocence on the ground that the unequivocal conclusion by

State’s expert on comparative microscopic matching did not create a substantial or 

significant possibility that the result at trial may have been different?1

Finding no abuse of discretion in the circuit court’s denial of the petition, we shall 

affirm. 

BACKGROUND 

For background, we set forth part of the factual summary from this Court’s 

unreported opinion in Patterson’s direct appeal: 

On July 9, 1992, Rudolph Holland was fatally shot at 49 Clay Street, near 

Annapolis, Maryland. Several witnesses testified that they saw two black 

men, one with dark skin, and the other with lighter skin, either in the area of 

the shooting or running from the scene. Although some were able to

identify [Patterson] as the man with the lighter skin, either by a photo array 

or in court, some were either unable positively to identify [him], or 

identified someone other than [him] as the man with the lighter skin. 

Officer William Hyatt, of the District of Columbia’s Metropolitan Police 

Department, was the State’s principal witness. Officer Hyatt testified that

on July 17, 1992, he responded to the area of 24th Street and Benning Road 

in Northeast Washington, D.C., after receiving a report that suspects in

another shooting were in that area. On arriving at the scene, Hyatt observed 

the three suspects, one of whom was later identified as [Patterson]. 

According to Officer Hyatt, [Patterson] and the other men fled, and 

 

1 Patterson phrased his question as follows: “Did the circuit court err in denying 

appellant’s writ for actual innocence on the basis that the ballistics examiner’s 

unequivocal conclusion regarding the murder weapon was a harmless error?” 
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[Patterson] discarded his gun after removing the bullets from it. [Patterson] 

was apprehended a short time later and placed under arrest for possession 

of a handgun. About four months later, [Patterson] was arrested by the 

Annapolis City Police Department for the Clay Street murder. At trial, a 

firearms examiner from the Federal Bureau of Investigation [“FBI”] 

testified that the bullet recovered from the victim of the Clay Street 

shooting had been from the .38 caliber gun dropped in Washington, D.C.,

by [Patterson] on July 17th. 

[Patterson], as well as several other witnesses for the defense, testified that

[he] was at a barbecue in Forestville, Maryland, on July 9th. [Patterson] 

testified that he did not have a gun with him on July 17th and thus could not 

have discarded a gun before being arrested.

Patterson v. State, No. 1932, Sept. Term 1993, slip op. at 1-2 (filed July 28, 1994) (per

curiam). 

Although it was not an issue during Patterson’s trial or direct appeal, the testimony 

of the FBI firearms examiner is now the subject of the instant appeal. That examiner, 

FBI Special Agent Joseph Williamson, testified, without objection, that the bullet 

recovered from the murder victim, as well as several other bullets recovered from the

Annapolis crime scene, had been fired by the .38 caliber handgun that Officer Hyatt had 

recovered from Patterson, “to the exclusion of any other firearm in the world.”

During closing argument, the prosecutor relied upon Special Agent Williamson’s 

unequivocal conclusion that the gun recovered from Patterson definitely fired the fatal 

shots. He told the jury that “the bullet was fired from this gun to the exclusion of all

handguns ever made anywhere in the world”; that “[n]o other gun anywhere in the world

could have fired those bullets except that one, that gun that was in the hands of Robert 

Patterson on July 17th”; and that the silver handgun, found in Patterson’s possession 
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eight days after the Annapolis murder, “definitely fired the bullets that killed Rudolph 

Holland[.]”

The prosecutor repeated these unequivocal assertions in the rebuttal phase of 

closing argument. There he told the jury that the “gun was analyzed by the F.B.I. and the 

bullets were tested by the F.B.I., and there’s no doubt that the gun and the bullets that Mr.

Patterson had in his hand were fired by that gun, the bullets that killed Mr. Holland.” He

concluded with the assertion that “[y]ou’ve got Mr. Patterson in Washington, D.C., in

possession of the gun that fired the bullets to the exclusion of all other guns in the world

that killed Rudolph C. Holland.”

The jury found Patterson guilty of first-degree murder, use of a handgun in the

commission of a crime of violence, and use of a handgun in the commission of a felony. 

The circuit court sentenced Patterson to a term of life imprisonment for first-degree 

murder and a consecutive term of 20 years’ imprisonment for one of the handgun 

convictions. 

In 1993, Patterson filed a motion for new trial on the ground of newly-discovered 

evidence – an affidavit, executed by an attorney who had investigated his case before 

trial, which contradicted the testimony of the arresting officer. The circuit court denied 

his motion, and this Court affirmed in an unreported opinion. Patterson v. State, supra,

No. 1932, Sept. Term 1993. Later, Patterson unsuccessfully pursued post-conviction 

relief. Patterson v. State, No. 25, Sept. Term 1998 (filed June 25, 1998) (per curiam);

Patterson v. State, No. 1355, Sept. Term 2010 (filed Mar. 24, 2011) (per curiam). 
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In 2013, Patterson, acting through counsel, filed a petition for a writ of actual

innocence. That petition alleged that Patterson’s trial had been tainted by the admission

of testimony, from Special Agent Williamson, regarding the use of comparative bulletlead analysis (“CBLA”), a technique that has been determined to be unreliable and 

inadmissible under the Frye-Reed test governing admissibility of scientific evidence in

Maryland courts. Clemons v. State, 392 Md. 339, 371 (2006). The circuit court

dismissed Patterson’s petition without a hearing because a review of the trial transcripts 

led it to determine that Special Agent Williamson “never used CBLA to link the bullets”

in Patterson’s possession “to the bullets found at the crime scene.”

Patterson, acting through the same counsel, filed a second petition for writ of 

actual innocence, which is the subject of the instant appeal. In that petition, Patterson 

challenged the State’s use of firearms identification evidence, which, as characterized by

Special Agent Williamson, is “a comparative microscopic study that permits the

identification of bullets and cartridge cases as having been . . . fired by a particular 

firearm to the exclusion of any other firearm.” 

“[C]omparative microscopic matching” “consists of attempting to identify the

‘toolmarks’ impressed upon the bullet fragments and cartridge casings often recovered

from a crime scene, in an effort to determine whether the toolmarks impressed upon the 

evidence could have been created by a firearm that has been connected to a suspect.” 

Fleming v. State, 194 Md. App. 76, 101 (2010). “The random imperfections in the bore 

of the firearm are theoretically unique to each firearm, and ‘the probability that another 

firearm would have identical bore imperfections is considered so remote that firearms 
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identification examiners often conclude that a bullet has been fired from a particular 

firearm and could not have been fired by any other firearm.’” Id. at 103 (quoting Paul C.

Giannelli & Edward J. Imwinkelried, Scientific Evidence § 14.03 (4th ed. 2007)). “In

making the inquiry into the similarity or near-identity of toolmarks, a trained firearm 

toolmark examiner uses a ‘comparison microscope’ to compare spent ammunition

components recovered from a crime scene with ammunition components fired from the

candidate firearm.” Id. (citing United States v. Monteiro, 407 F. Supp. 2d 351, 359 (D.

Mass. 2006)). “Ultimately, the determination of whether a potential ‘match’ exists is

made by a trained examiner using a split-screen microscope to simultaneously compare 

the toolmarks on the crime scene evidence against the toolmarks produced by a test round 

fired by the subject firearm.” Id. at 104 (citing Monteiro, 407 F. Supp. 2d at 355). 

Citing recent studies and court decisions that allegedly reveal the limitations of 

drawing the unequivocal conclusions that Special Agent Williamson expressed, Patterson 

claims to have identified newly-discovered evidence, which could not have been 

discovered through the exercise of due diligence in time to file a motion for new trial

under Md. Rule 4-331(c), but which creates a substantial possibility that, had this 

evidence been admitted during his 1993 trial, a different outcome would have resulted. 

The circuit court conducted a hearing on Patterson’s petition. In a written opinion, 

the court concluded that the evidence would not have substantially affected the jury’s 

verdict. Accordingly, it denied the petition. 

Patterson noted this timely appeal. 
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DISCUSSION 

I.

A petition for writ of actual innocence, under Maryland Code (2001, 2008 Repl. 

Vol., 2015 Supp.), § 8-301 of the Criminal Procedure Article (“CP”), gives a convicted 

person “an opportunity to seek a new trial based on newly discovered evidence that 

speaks to his or her actual innocence[.]” Douglas v. State, 423 Md. 156, 176 (2011). 

Section 8-301 gives a person this opportunity by establishing the functional equivalent of 

a motion for new trial on the ground of newly-discovered evidence, but without the strict 

time limits imposed by Maryland Rule 4-331(c). See Douglas, 423 Md. at 176.2 The

statute provides in pertinent part: 

(a) A person charged by indictment or criminal information with a crime 

triable in circuit court and convicted of that crime may, at any time, file a 

petition for writ of actual innocence in the circuit court for the county in

which the conviction was imposed if the person claims that there is newly 

discovered evidence that: 

(1) creates a substantial or significant possibility that the result may 

have been different, as that standard has been judicially determined; and 

(2) could not have been discovered in time to move for a new trial

under Maryland Rule 4-331. 

CP § 8-301(a). 

 

2 Rule 4-331(c) authorizes the court to grant a new trial based on newly discovered 

evidence that could not have been discovered by due diligence in time to move for a new 

trial within 10 days after the verdict. Such a motion must be filed “within one year after 

the later of (A) the date the court imposed sentence or (B) the date the court received a 

mandate issued by the final appellate court to consider a direct appeal from the judgment 

or a belated appeal permitted as post conviction relief[.]” Md. Rule 4-331(c)(1). 
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In brief summary, § 8-301(a) imposes three requirements upon a petitioner: (1) he 

or she must come forward with “newly discovered evidence”; which (2) “creates a 

substantial or significant possibility that the result [of his or her trial3] may have been 

different”; and which (3) “could not have been discovered in time to move for a new trial

under Maryland Rule 4-331,” a requirement known as “due diligence.” If a petitioner 

substantially complies with the requirements of CP § 8-301(b) and Rule 4-332(d) and

asserts grounds that could, if proven, entitle the petitioner to relief, then he or she is

entitled to a hearing on that petition. CP § 8-301(e); Md. Rule 4-332(j)(1); State v. Hunt, 

443 Md. 238, 250-51 (2015). 

In a proceeding under CP § 8-301, the petitioner bears the burden of proof. CP § 

8-301(g); Md. Rule 4-332(k). That burden stands in stark contrast to an appellant’s

burden in a direct appeal from a criminal conviction. If an appellant establishes error in a 

direct appeal from a criminal conviction, the burden shifts to the State to show “‘that the

error in no way influenced the verdict.’” Dionas v. State, 436 Md. 97, 108 (2013) 

(quoting Dorsey v. State, 276 Md. 638, 659 (1976)). By contrast, in a petition for a writ

of actual innocence, the petitioner must show that “there [is] a substantial possibility that 

a different result would have occurred in the trial, whether jury or bench, as a result of the

newly discovered evidence.” Yonga v. State, 446 Md. 183, 208 (2016); see CP § 8-

 

3

In Yonga v. State, 446 Md. 183 (2016), the Court of Appeals held that if a person 

is convicted after pleading guilty, he or she is ineligible to seek relief under the actual 

innocence statute. 
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301(a)(1) (petitioner must show “a substantial or significant possibility that the result 

may have been different”). 

Because the circuit court denied Patterson’s petition on the merits after a hearing, 

we review the circuit court’s decision to deny that petition for abuse of discretion. Hunt,

443 Md. at 247-48; Snead v. State, 224 Md. App. 99, 109 (2015). Under that standard, 

this Court “will not disturb the circuit court’s ruling, unless it is ‘well removed from any 

center mark imagined by the reviewing court and beyond the fringe of what the court

deems minimally acceptable.’” McGhie v. State, 224 Md. App. 286, 298 (2015)

(“McGhie I”) (quoting Jackson v. State, 216 Md. App. 347, 363-64 (2014) (further 

quotation marks omitted)), aff’d, ___ Md. ___, 2016 WL 4470907 (Aug. 24, 2016) 

(“McGhie II”). 

II.

Patterson contends that the circuit court abused its discretion in denying his 

petition because, he says, the State’s expert in comparative microscopic matching, 

Special Agent Williamson, was erroneously permitted to testify that the .38 caliber 

revolver, recovered from him in Washington, D.C., fired the fatal shots “to the exclusion 

of any other firearm in the world.” He points out that the State relied upon that testimony 

both in closing argument and rebuttal. On that basis, he concludes that the alleged error

“contributed to the verdict.” 

In support of his claim of error, Patterson cites “recent scientific studies and the

emerging scholarly literature and case law recognizing the limitations of firearms 

identification for making such emphatic and unequivocal conclusions.” He relies upon 
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the following authorities: Adina Schwartz, A Systemic Challenge to the Reliability and 

Admissibility of Firearms and Toolmark Identification, 6 Colum. Sci. & Tech. L. Rev. 2 

(2005); National Research Council of the National Academies, Strengthening Forensic 

Science in the United States: A Path Forward (The National Academies Press 2009), 

available at https://www.ncjrs.gov/pdffiles1/nij/grants/228091.pdf (last visited Aug. 4,

2016); and Richard Gryzbowski, et al., Firearms/Toolmark Identification: Passing the

Reliability Test Under Federal and State Evidentiary Standards, 35 AFTE J. 209 (2003); 

and several court decisions, including United States v. Otero, 849 F. Supp. 2d 425 (D.N.J. 

2012); United States v. Willock, 696 F. Supp. 2d 536 (D. Md. 2010); United States v.

Glynn, 578 F. Supp. 2d 567 (S.D.N.Y. 2008); United States v. Monteiro, 407 F. Supp. 2d 

351 (D. Mass. 2006); United States v. Green, 405 F. Supp. 2d 104 (D. Mass. 2005); and 

People v. Robinson, 2 N.E.3d 383 (Ill. App. Ct. 2013).4

Patterson contends that those studies, articles, and court decisions comprise newlydiscovered evidence, which could not have been discovered through the exercise of due 

diligence in time to file a motion for new trial under Md. Rule 4-331(c), but which create

 

4 The cited cases are not overwhelmingly helpful to Patterson. In Willock, 696 F.

Supp. 2d at 571, Judge Paul Grimm found that the “theory of firearms-related toolmark 

identification” was “generally accepted within the field of toolmark examiners.” In

Otero, 849 F. Supp. 2d at 437-38, the court held that a toolmark identification opinion 

was admissible. In Glynn, 578 F. Supp. 2d at 574, the court expressed reservations about 

“ballistics examination,” but concluded that the “methodology ha[d] garnered sufficient

empirical support as to warrant its admissibility.” In Monteiro, 407 F. Supp. 2d at 372, 

the court “conclude[d] that the methodology of firearms identification is sufficiently 

reliable.” In Green, 405 F. Supp. 2d at 109, the court “reluctantly” admitted firearm 

toolmark evidence because of its “confidence” that the appellate court would reject a 

contrary decision. 
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a substantial possibility that, had this evidence been admitted during his 1993 trial, a 

different outcome would have resulted. In effect, he maintains that his 1993 convictions 

were based upon junk science. 

III. 

We assume for the sake of argument that Patterson has identified newlydiscovered evidence that could not have been discovered through the exercise of due 

diligence in time to file a motion for new trial under Md. Rule 4-331(c).5

 Even on that

assumption, the circuit court did not abuse its discretion in concluding that Patterson had 

failed to discharge his burden of showing “a substantial possibility that a different result

would have occurred in the trial . . . as a result of the newly discovered evidence.” 

Yonga, 446 Md. at 208. 

As recently as 2010, this Court confirmed that comparative microscopic matching 

is still generally accepted within the scientific community and is, for that reason,

admissible under the Frye-Reed standard for evaluating the introduction of expert

testimony. See Fleming, 194 Md. App. at 106-07. In upholding a first-degree murder

conviction in that case, this Court observed that in Reed v. State, 283 Md. 374 (1978), the 

 

5 Although scientific studies unquestionably can qualify as newly-discovered 

evidence (Ward v. State, 221 Md. App. 146, 163 (2015)), some of the scientific

information does not appear to be particularly new. As the State points out, one of 

Patterson’s principal authorities cites a 1955 study. Adina Schwartz, A Systemic

Challenge to the Reliability and Admissibility of Firearms and Toolmark Identification,

supra, 6 Colum. Sci. & Tech. L. Rev. at 14. Another authority cites studies, published in

1959 and 1984, which questioned the statistical foundation underlying comparative 

microscopic matching. National Research Council of the National Academies, 

Strengthening Forensic Science in the United States, supra, at 154 n.63. 
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very case that adopted what we now know as the Frye-Reed standard, the Court of 

Appeals “referred to ‘ballistics’ as an example of a discipline for which ‘the validity and

reliability is so broadly and generally accepted’ that . . . ‘a trial court may take judicial 

notice of its reliability.’” Fleming, 194 Md. App. at 107 (quoting Reed, 283 Md. at 380). 

The discipline of “firearms toolmark identification” is widely (though incorrectly) known 

as “ballistics.” Id. at 100 n.2.6

In Fleming we recognized that comparative microscopic matching or toolmark 

identification involves subjective judgments by the examiner. Id. at 104 (citing United

States v. Monteiro, 407 F. Supp. 2d 351, 355 (D. Mass. 2006); Paul C. Giannelli & 

Edward J. Imwinkelried, Scientific Evidence, supra, § 14.03). We also recognized that

some have criticized comparative microscopic matching because of “the inherent

subjectivity of the examiner’s ultimate determination.” Id. at 105. Nonetheless, we

concluded that the circuit court did not err in admitting expert testimony that used 

comparative microscopic matching, because it remains generally accepted within the

scientific community. Id. at 109.7

 

6 Firearms toolmark identification, which is “the practice of investigating whether

a bullet, cartridge case or other ammunition component or fragment can be traced to a 

particular suspect weapon” (Fleming, 194 Md. App. at 100-01), does not directly involve

ballistics, which is “‘the study of the motion of a projectile[,]’” including the projectile’s 

motion within the firearm and the projectile’s effect on the target outside the firearm. Id.

at 100 n.2 (quoting P. Giannelli & E. Imwinkelried, Scientific Evidence § 14.01, at 707 

(4th ed. 2007)). 

7 That conclusion was in the nature of a demi-holding: we had previously held that 

any error in admitting the testimony would have been harmless beyond a reasonable 

doubt because of the abundance of evidence that Fleming had fired the weapon in
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If comparative microscopic matching is generally accepted within the scientific

community even in 2016, it is inconceivable that the assorted criticisms, assembled by

Patterson, would have resulted in a different outcome had he been able to present them at

his initial trial in 1993. Compare Ward v. State, 221 Md. App. 146, 167-70 (2015) 

(vacating denial of a petition for writ of actual innocence, where newly-discovered 

evidence would have prevented expert from offering opinion based on discredited theory 

of CBLA). Unlike CBLA testimony, comparative microscopic matching is as admissible 

today as it was in 1993. 

Patterson counters that, in light of his criticisms of comparative microscopic

matching, a court would not have permitted Special Agent Williamson to express his 

opinions with absolute certainty, as he did at the 1993 trial. Yet, as the circuit court 

recognized in denying Patterson’s petition for a writ of actual innocence, the agent would

still have been permitted to testify, to a reasonable degree of certainty within his field of 

expertise, that the bullet that was found in the victim’s body was shot out of the gun that

Patterson attempted to discard just before his arrest in the District of Columbia. Hence, 

had the jury considered the “newly-discovered” evidence concerning toolmark 

identification, it might have assigned less weight to the agent’s testimony, but most

probably would not have discounted his testimony in its entirety. Compare McGhie II, 

 

question. Fleming, 194 Md. App. at 99. That evidence included the testimony of three

eyewitnesses, as well as the testimony of Fleming’s step-grandfather, who linked

Fleming to the weapon. Id. On the basis of that testimony, Fleming’s counsel had 

conceded that Fleming fired the weapon; his sole defense had been that he did not intend

to kill his victim. 
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___ Md. at ___, 2016 WL 4470907, at *9 (reasoning that there was a substantial or 

significant possibility that a jury might have discounted an expert’s testimony “in its

entirety” had it known that the expert had lied about his academic credentials). 

In our view, the court was not “well removed from any center mark imagined by

the reviewing court and beyond the fringe of what the court deems minimally acceptable”

(McGhie I, 224 Md. App. at 298), when it was unpersuaded that the jury may have 

reached a different conclusion solely because of a semantic variation in the degree of 

certainty with which the FBI agent could have expressed his opinions. In light of the

inculpatory testimony that the agent could properly have given, as well as the other 

evidence against Patterson, including the testimony of two eyewitnesses who placed him 

at or near the scene of the murder, the circuit court did not abuse its discretion in

concluding that he had failed to discharge his burden. See McGhie II, ___ Md. at ___, 

2016 WL 4470907, at *10; McGhie I, 224 Md. App. at 305-06. 

In McGhie the petitioner came forward with newly-discovered evidence that the

State’s ballistics expert had lied about his qualifications. See McGhie I, 224 Md. App. at

293. The hearing judge nonetheless denied the petition, reasoning that, even without the

ballistics evidence, there was “‘ample testimony” from other witnesses that directly 

implicated the petitioner. Id. at 304 (quoting the circuit court). Both this Court and the

Court of Appeals concluded that the circuit court did not abuse its discretion in

concluding that the petitioner had not met his burden of showing that the newlydiscovered evidence would have created a substantial or significant possibility of a 

different result. See McGhie II, ___ Md. at ___, 2016 WL 4470907, at *10 (no abuse of 
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discretion in denying actual innocence petition “given the weight of the evidence

presented against [the petitioner] at trial”); McGhie I, 224 Md. App. at 305-06 (no abuse

of discretion in denying petition where there was “other compelling evidence” of guilt). 

If it was not an abuse of discretion for a circuit court to conclude that an expert’s lies 

failed to overcome other compelling evidence of guilt, then it could not be an abuse of 

discretion to conclude, as the circuit court did in this case, that an expert’s undue 

emphasis on the certainty of his conclusions did not overcome the other compelling 

evidence of Patterson’s guilt, including the inculpatory testimony that the expert could 

properly have given. 

JUDGMENT OF THE CIRCUIT COURT 

FOR ANNE ARUNDEL COUNTY 

AFFIRMED. COSTS ASSESSED TO

APPELLANT.