People v. Wakefield

• Decision Date: 26 April 2022
• Docket Number: 3
• Citation: 38 N.Y.3d 367,195 N.E.3d 19,174 N.Y.S.3d 312
• Parties: The PEOPLE of the State of New York, Respondent, v. John WAKEFIELD, Appellant.
• Court: New York Court of Appeals Court of Appeals

38 N.Y.3d 367
195 N.E.3d 19
174 N.Y.S.3d 312

The PEOPLE of the State of New York, Respondent,
v.
John WAKEFIELD, Appellant.

No. 3

Court of Appeals of New York.

Decided April 26, 2022

195 N.E.3d 21

174 N.Y.S.3d 314

Hug Law, PLLC, Albany (Matthew C. Hug of counsel), for appellant.

Robert M. Carney, District Attorney, Schenectady (Peter H. Willis of counsel), for respondent.

OPINION OF THE COURT

Chief Judge DiFIORE.

38 N.Y.3d 371

This appeal primarily concerns the admissibility of DNA mixture interpretation evidence generated by the TrueAllele Casework System. We conclude that Supreme Court did not abuse its discretion in finding, following a Frye hearing, that TrueAllele's use of the continuous probabilistic genotyping approach to generate a statistical likelihood ratio—including the use of peak data below the stochastic threshold—of a DNA genotype is generally accepted in the relevant scientific community. We also hold that there was no error in the court's denial of defendant's request for discovery of the TrueAllele software source code in connection with the Frye hearing or for the purpose of his Sixth Amendment right to confront the witness against him at trial.

I.

On April 12, 2010, the victim was found strangled to death in his apartment, with a guitar amplifier cord wrapped around his neck. Several items had been stolen from the victim's home, including a PlayStation 3, a laptop and a distinctive orange duffel bag. Witnesses observed defendant in the company of the victim the weekend of the homicide and defendant admitted to three individuals that he had choked the victim. Defendant did not dispute that he had been present at the victim's home. A separate witness observed defendant with a distinctive orange duffel bag like the one belonging to the victim, attempting to trade a PlayStation and a laptop for drugs. The victim's PlayStation 3 was recovered from the home of a local drug dealer.

At the scene, the police collected DNA samples from several items of evidence and sent them to the New York State Police Forensic Investigation Center (Lab) for PCR DNA typing analysis, using the FBI-selected 15 STR loci standard.¹ Defendant's single-source DNA profile was developed from two bottles taken from the victim's home. Relevant to the issues presented here are four DNA profiles developed by the Lab through the

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samples

174 N.Y.S.3d 315

195 N.E.3d 22

taken from the front and rear outside collar of the victim's shirt, the victim's dorsal forearm and a section of the amplifier cord used to strangle the victim. The DNA test results developed by the Lab in an electropherogram were then compared to known DNA profiles from defendant and the victim. The Lab concluded that: 1) the two profiles generated from the shirt collar were consistent with at least two donors, one of which was the victim, and defendant could not be excluded as the other contributor; 2) the DNA mixture from the right dorsal forearm was consistent with DNA from the victim, as the major contributor, mixed with at least two additional donors; and 3) the amplifier cord was a mixture of at least two donors, from which the victim could not be excluded as a possible contributor. The results generated from the amplifier cord were not compared to defendant's DNA profile because of the complexity of the mixture.

Since the Lab used an interpretation standard of a stochastic threshold of 50 to 100 relative fluorescence units (RFU), the analyst did not call any alleles based on peaks on the electropherogram below that threshold. As a result, there was insufficient data to allow the Lab to calculate probabilities for the unknown contributors to the DNA mixtures found on the amplifier cord and the front of the shirt collar. The Lab was able to call only 4 out of 15 STR loci and the analyst, using the combined probability of inclusion method,² generated a statistic that the probability an unrelated individual contributed DNA to the outside rear shirt collar was 1 in 1,088. Using the same number of loci for the profile obtained from the victim's forearm, the analyst generated a statistic that the probability an unrelated individual contributed DNA to the profile was 1 in 422.

The electronic data from the DNA testing of the four samples at issue was then sent to Cybergenetics for additional analysis because its TrueAllele Casework System applies a continuous probabilistic genotyping method of calculating a likelihood ratio—using all of the information generated on the electropherogram, including peaks that fall below a laboratory's stochastic threshold. The likelihood ratio in its modern form was developed by Alan Turing during World War II as a code-breaking method. TrueAllele uses a probability model to assess

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the values of a genotype objectively. It does not consider a reference sample for any particular DNA profile. Following protocol, once the genotypes were inferred based on mathematical computations from all the data in the electropherograms, the system compared defendant's genotype to all of the statistical genotype possibilities and calculated likelihood ratios as to the presence of defendant's genotype. The ratios were exponentially greater than those generated by the methods employed by the Lab. Specifically, TrueAllele concluded that it was 5.88 billion times more probable that defendant was a contributor to the mixture on the amplifier cord than an unrelated black person, that it was 170 quintillion times more probable that defendant was a contributor to the mixture on the outside rear shirt collar than an unrelated black person, that it was 303 billion times more probable that defendant was a contributor to the mixture on the outside front shirt collar than an unrelated black person, and that it was 56.1 million times more probable that defendant was a contributor to the mixture

174 N.Y.S.3d 316

195 N.E.3d 23

on the victim's dorsal forearm than an unrelated black person.

Prior to trial, in March 2014, defendant moved to preclude the introduction of any evidence or testimony derived from the TrueAllele Casework System or, in the alternative, for a Frye hearing to determine the general acceptance of TrueAllele in the relevant scientific community. Defense counsel acknowledged having received from the People approximately 1,500 pages of discovery documents, including reports relating to the DNA analysis, but argued that several additional items "must be disclosed"—specifically, the defense sought the "assumptions" and parameters programmed into the TrueAllele system and the software's source code.

In support of the motion, defendant submitted an affidavit from Ranajit Chakraborty, Ph.D.—a member of the Scientific Working Group on DNA Analysis Methods (SWGDAM)³ and former member of the New York State Commission on Forensic Science DNA Subcommittee. Parenthetically, the DNA subcommittee is charged by Executive Law § 995–b (13) to "assess and evaluate all DNA methodologies proposed to be used for forensic analysis" in the state. Dr. Chakraborty acknowledged

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that both New York's DNA Subcommittee and the full Commission on Forensic Science (CFS) approved TrueAllele for forensic casework without limitation in 2011 while he was a member. However, since TrueAllele "re-analyzes" the electronic data from another laboratory by including "all allele peak height information including that which extends below" the stochastic threshold, he maintained that it was a novel innovation which had not gained general acceptance in the scientific community. Dr. Chakraborty opined that, when the DNA Subcommittee approved TrueAllele, it had not been presented with evidence of its ability to analyze certain types of complex DNA mixtures and that it "ha[d] not been adequately validated for the type of casework [to which] it is now being applied." Dr. Chakraborty contended that, in the absence of disclosure of the source code for the software and the underlying assumptions programmed into the system, "TrueAllele cannot be meaningfully validated."

Supreme Court granted defendant's motion to the extent of ordering a Frye hearing to determine the admissibility of TrueAllele's methodology.

In July 2014, prior to the Frye hearing, defense counsel made a supplemental demand for discovery seeking several items relating to the TrueAllele process including, as relevant here, the TrueAllele source code. The People, who were not in possession of the source code, denied the request as the source code was outside the scope of the former demand discovery provision, CPL 240.20.

The Frye hearing commenced in October 2014 and the People called three witnesses—Dr. Mark Perlin from Cybergenetics, and Dr. Barry Duceman and forensic analyst Jay Caponera from the Lab. Dr. Perlin, who has a medical degree as well as a Ph.D. in both mathematics and computer science, founded Cybergenetics in 1994 and is its Chief Scientist and Executive Officer. He testified that TrueAllele is comprised of two systems—TrueAllele Databank, for interpreting single-source reference samples (used by the New York State Police for the state DNA databank), and TrueAllele Casework, for interpreting

174 N.Y.S.3d 317

195 N.E.3d 24

more complex DNA mixtures. The True Allele Casework System does not generate a DNA profile, but analyzes the electronic raw data that has already been generated by a forensic crime lab, separates (or deconvolutes) the genotypes and calculates the

38 N.Y.3d 375

likelihood ratio.⁴ As described at the hearing, the analyst operating the TrueAllele system reviews the raw electronic data and then inputs the data file into the computer, setting parameters such as the number of contributors and the quality of the mixture. The computer then separates the genotypes using the mathematical probability principle of the Markov chain Monte Carlo (MCMC) search to calculate the probability for what the different genotypes could be. The computer conducts a quantitative analysis using all of the electronic...