1

See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 597 (1993) (holding the rules

of evidence assign to a trial judge “the task of ensuring that an expert’s testimony both rests on a

reliable foundation and is relevant to the task at hand.”). As will be discussed, infra, this case

ultimately did not involve a Daubert issue.

2

 When a population contains nine or fewer items, the hypergeometric sampling plan does

not apply. See Hypergeometric Sampling Table, attached hereto as Exhibit A.

SUPERIOR COURT

OF THE

STATE OF DELAWARE

T. HENLEY GRAVES SUSSEX COUNTY COURTHOUSE

RESIDENT JUDGE 1 THE CIRCLE, SUITE 2

GEORGETOWN, DE 19947

(302) 856-5257

September 17, 2015

Caroline Brittingham, Esquire

Department of Justice

114 E. Market Street

Georgetown, DE 19947

Jerome Capone, Esquire

Office of the Public Defender

14 The Circle, 2nd Floor

Georgetown, DE 19947

RE: State vs. Richard Roundtree

Case No: 1412017602

Dear Counsel:

This is the Court’s written decision following its bench ruling issued on September 14, 2015,

that granted the State’s Motion to allow hypergeometric sampling of suspected drugs when a large

quantity is involved. The Court held a Daubert hearing over the course of two days.1 The issue

before the Court is narrow: whether hypergeometric sampling may be used by the Division of Safety

and Homeland Security, Division of Forensic Science (hereinafter, “DFS”) to test only a portion of

seized drugs in large volume cases.2

On September 11, 2015, the State presented two experts, John Mario, a forensic scientist
2

formerly with the Suffolk County Crime Laboratory of New York, and Dr. Bradley Venner, a

statistician with the Environmental Protection Agency. On September 14, 2015, the State presented

the testimony of Robyn Quinn, DFS’ forensic testing supervisor, and Melissa Newell, the chemist

who tested the drugs in this particular case. The defense argued that hypergeometric testing was not

as reliable as testing to weight but did not offer any witness testimony to support its argument.

After hearing the evidence, the Court concludes the matter before it is not a typical Daubert

issue, in that the issue is not whether to accept or reject a new technology or scientific theory. This

matter concerns the day-to-day operations in drug laboratories and the subsequent use of evidence

in a criminal trial. The question before the Court is: Does the hypergeometric method of sampling

in drug cases permit an inference upon which the jury can reasonably rely to satisfy the State’s

burden of proof? Thus, this issue is really a sufficiency of the evidence argument.

This case does not pertain to the chemical analysis of suspected drug evidence. Rather, the

question is how much of the seized drug evidence must be actually tested by the chemist.

Mr. Mario, a chemical forensic scientist, provided the Court with a brief overview of the field

of forensic drug testing. He testified that the laboratory with which he had been affiliated from 1981

through his retirement in 2013 uses hypergeometric testing. Mr. Mario was a member of the Core

Committee of the Scientific Working Group for the Analysis of Seized Drugs (“SWGDRUG”) from

1998 until he retired in 2013. He continues to consult with the Springfield Massachusetts Police

Department in a drug evidence audit.

Mr. Mario testified that SWGDRUG cannot publish standards, per se, but can make

recommendations to the international forensic community. SWGDRUG endorses statistical

sampling and supports the hypergeometric approach. The American Society for Testing and
3

 One of the laboratories reviewed was Delaware’s DFS.

3

Materials (“ASTM”) publishes standards. Their standards are reviewed every five years and updated

as needed. ASTM has adopted SWGDRUG’s recommendation on sampling. The International

Organization for Standardization/International Electrotechnical Commission (“IOS/IEC”) is,

according to Mr. Mario and not refuted by the defense, the leading standard for testing laboratories

and provides that laboratories must have a sampling plan and procedures in place.

Mr. Mario told the Court that a review of seventeen sampling plans from around the United

States, including two federal laboratories, revealed that all of them employ the hypergeometric

probability distribution approach when they conduct sampling.3 Among these laboratories are the

New York State Police Forensic Center, the Virginia Department of Forensic Science, the Texas

Department of Public Safety, the Massachusetts State Police, and the United States Drug

Enforcement Administration. The State presented ample evidence that the hypergeometric sampling

model is well entrenched in drug testing laboratories.

Dr. Venner testified that hypergeometric sampling is a reasonably relied upon probability

model that is used not only in testing drug samples, but also for all sorts of commercial sampling.

It is based upon solid mathematical and statistical grounds and was recognized centuries ago and has

since been refined.

To a degree this is much ado about nothing, or perhaps deja vu all over again because we

learned that the hypergeometric model was used in Delaware by the Office of the Chief Medical

Examiner (“OCME”) prior to its closure. I suspect it was such an imbedded practice, issues as to

its use never arose. The current notoriety of the method seems to stem from the objection to the

policy of the Pennsylvanian laboratory, NMS, of only testing nine or ten samples, regardless of the
4

 The drugs in this case were initially sent to NMS for testing.

4

population of items seized.4 This is an acceptable procedure in Pennsylvania, but its drug laws are

different and, in fact, currently under revision. In Pennsylvania and some other jurisdictions, it is

permissible to make a general or arbitrary inference argument to the jury that, if all ten (10) samples

tested positive for heroin, it can infer the balance of the seized items would test positive for heroin.

In this case, the Court rejected this general inference approach by way of a bench ruling on August

12, 2015. The Court was not satisfied that a general inference satisfied a sufficiency of the evidence

threshold. Interestingly, having lost this initial battle, the State acknowledged in its written

submission to the Court that there are problems with the arbitrary inference approach.

The polar opposite of permitting a general or arbitrary inference would be to require the

prosecution actually test that amount of drugs required for conviction under the criminal statutes, i.e.,

that DFS test to the weight. This Court could only locate one jurisdiction, Illinois, that requires the

prosecution meet this strict standard.

The hypergeometric sampling methodology allows the testing laboratory to test a portion of

the seized drugs, and, based upon those test results, infer certain conclusions about the balance of

the untested seized drugs. It is a statistical model based upon a mathematical formula that produces

a statistical inference that, if a certain number of randomly selected samples are tested and all test

positive, then it is probable that most of the remaining items would likewise test positive if actually

tested. 

The number of samples that must be tested has a direct statistical relationship as to the

conclusion on probability. In the drug testing world, the standard confidence and probability

percentages requires that the number of samples tested produce a 95% confidence level that at least
5

90% of the remaining population is of the same composition as what was tested.

At the hearing, the Court also learned that a major driver for the use of hypergeometric

sampling model is not only the reliability of its probability inference, but also its practicality.

Testing to the weight requires much more time and State resources. The evidence showed that, in

Delaware, it would be impractical, if not impossible, to test to the weight without a huge influx of

money and resources into DFS.

Ms. Quinn, DFS’ laboratory manager, testified DFS is licensed by the American National

Standards Institute-American Society for Quality National Accreditation Board (“ANSI-ASQ”).

DFS also has ISO/IEC 17025 accreditation, which is issued by the ANSI-ASQ. As noted,supra, the

ISO/IEC 17025 standards require the laboratory have a sampling plan and procedures for sampling.

Ms. Quinn’s responsibilities include ensuring DFS’ forensic chemistry unit is in compliance with

ISO/IEC 17025.

Ms. Quinn was a laboratory manager at OCME and has been the laboratory manager since

DFS reopened under its new incarnation in January of 2015. When Ms. Quinn took her position, she

testified that she made changes to the sampling model to make it “more conservative.” In so doing,

she relied upon SWGDRUG’s recommendations and other laboratories’ policies. All of the

laboratories from which she sought input use hypergeometric testing.

Ms. Quinn testified that there are five chemists at the Delaware lab. There are only three Gas

Chromatography-Mass Spectrometry instruments (“GC-MS”), the machines utilized to identify

substances in a test sample. Two are currently “on line” and available for use.
5

 In point of fact, there were originally 399 bags in this case. However, ten of those were

tested by NMS. The remaining 389 bags were sent to DFS for testing.

6

See Exhibit A.

6

In the present case, DFS received 389 bags of suspected heroin.5 The table for determining

the number of samples to be tested under the hypergeometric model requires 28 randomly selected

samples to be tested.

6

 Ms. Quinn testified that, if all 389 bags had to be tested, it would take

approximately thirty (30) hours of prep time plus ninety-seven (97) hours of machine time to

complete the GC-MS analysis. Although the instrument is programed to run on its own, when a

machine is in use it is not available for other testing.

The impracticality of testing to weight increases as the tier level for a drug offense increases.

For example, a tier five heroin offense requires that a defendant have five (5) grams or more of

heroin. Ms. Quinn testified that, based upon the average amount of heroin found in a bag of heroin

in this case (.004 grams), five (5) grams of heroin could be contained in as many as 1250 bags of

heroin. Ms. Quinn opined it would take one chemist close to 390 hours to test 1250 bags.

With this said, practicality and limited resources should not dictate the Court’s acceptance

of shortcuts. Thus, this Court did not accept the general or arbitrary inference theory first proposed

by the State.

The hypergeometric model for sampling may be a time saver, but it is a statistically and

mathematically sound method of providing the jury a statistically based and probability based

inference as to the untested items. It allows for a reasonable inference based upon a mathematical

and statistical model. Ultimately, the jury must decide whether the inference supports a conviction

or whether the State’s evidence falls short of its burden. For purposes of this motion, the Court finds
7

See Ohio v. Gartrell, 24 N.E.3d 680, 707 (Ohio 2014) (holding evidence of

hypergeometric sampling is “sufficient as a matter of law to support a determination that the

entire substance recovered together and similarly packaged is the same controlled substance as

that tested”) (citation and internal quotation marks omitted).

7

that the hypergeometric methodology of sampling provides sufficient evidence for the State to get

to the jury.7 

The Court notes that the State’s expert witness, Mr. Mario, reviewed the State’s

hypergeometric testing protocol. That protocol tracks the standard operating procedure for the other

laboratories and agencies that use hypergeometric sampling.

In each future case where the State relies upon the laboratory’s sampling table attached to this

decision, the State must still satisfy the requirements for proper hypergeometrical sampling; to wit,

the State must show how a determination as to the homogeneity of the tested population was made

and how the tested samples were randomly selected. Homogeneity requires the chemist to inspect

visually each seized item to determine if the items are so similar in physical appearance that they

would be included in a single population. In the present case, Ms. Newell visually inspected the

exterior of all 389 bags (also known as bindles). Ms. Newell testified the bags were all of similar

appearance; in same size, blue bags; and stamped with the notation “Erruption” in the same color

ink. Ms. Newell stated that, had she found any bags that were not similar in appearance, she would

have segregated the dissimilar bags into a different population pool.

After the population has been determined, the samples to be tested must be randomly

selected. In this case, after counting the bags and making a homogeneity determination, Ms. Newell

placed the bags back into a common container and randomly selected the requisite twenty-eight, per

the hypergeometric sampling table. Dr. Venner testified that, in his expert opinion, this method of
8

 As an aside, Ms. Quinn seemed baffled when the Court inquired about the potential

effect a negative result in the sampled group would have; in her experience, she had never

encountered such a scenario.

8

random selection is an accepted practice. The twenty-eight samples were weighed and tested. All

tested positive for heroin. Therefore, the chemist concluded with 95% confidence the probability

was that 90% of the entire population of bags contained heroin. In conclusion, the hypergeometric

model provided September 17, 2015 a statistical probability inference as to what was in the bags;

i.e., heroin.

The Court notes Dr. Venner testified that, had one or two samples tested negative, the

hypergeometric model could still be used, but a different mathematical formula would be utilized,

presumably creating a different table. The Court’s decision only addresses the mathematical formula

used when all the tested samples test positive.8

In this decision, the Court accepts the validity of hypergeometric sampling. The Court

recognizes that if protocol is followed and all of the samples test positive, there exists a statistical

probability permitting an inference with a 95% confidence level that 90% of the population contains

the same substance as the tested samples. The Court will not require this statistical probability to

be proven again and again with expert testimony in the future.

The Court will, of course, permit the attorneys to argue their respective positions as to the

inferences that may be made from the use of hypergeometric testing because the jury ultimately

decides whether it is satisfied the State has met its burden of proof.

Hypergeometric sampling is used onlyfor determining the probability of the entire population

containing the same substance. It tests each sample to determine one of two things: positive for

controlled substance or negative. Hypergeometric sampling is not used to determine the total weight;
9

weight is determined by another process. The current lab does exactly what the OCME with regard

to making a total weight determination. In this case, Ms. Newell weighed the contents of the opened

and tested bags. She took an average of those twenty-eight bags and extrapolated the total weight

of the 389 bindles. Using this averaging process, a chemist does not open all 389 bags. The Court

suspects there are other methods of determining weight; for example, taking the total weight of all

389 bags and contents, then weighing out the average of the bag alone, which should be consistent,

and then subtracting the weight of 389 bags only from the total. Again, this method was not the

focus of the hearing because the hypergeometric model is only used to determine the probability

inference of identifying the substance. 

The Motion to permit the use of hypergeometric sampling is granted. 

IT IS SO ORDERED.

Very truly yours,

/s/ T. Henley Graves

T. Henley Graves

THG/ymp

pc: Prothonotary

Valerie Dunkle, Esquire