People v. Pike

53 N.E.3d 147 (2016)

Facts

D was arraigned and appointed a public defender. D asked to proceed pro se. During the trial, forensic scientist Katrina Gomez was accepted as an expert in forensic biology and DNA analysis without objection. Gomez was assigned to analyze the evidence collected in this case. Gomez was trained in short tandem repeat (STR) polymerase chain reaction (PCR) DNA testing and testified that the swabs did not contain sufficient DNA to develop a profile. Gomez then spoke with forensic scientist Lisa Fallara about the possibility of performing Y-chromosome STR (Y-STR) analysis on the DNA extract from the gun swabs. Gomez then sealed the items and forwarded them to Fallara for Y-STR testing. Fallara testified that Y-STR testing is generally accepted in the scientific community. Whereas traditional DNA testing looks at several areas of DNA along with several different chromosomes, Y-STR testing looks at several different locations only on the male Y chromosome; it is essentially male DNA testing. Fallara explained that Y chromosome DNA is passed down from the paternal line so that a brother, father, and father's father will all have the same Y-STR DNA profile. Fallara explained that Y-STR analysis is better suited for obtaining profiles from a limited amount of DNA. Fallara testified that Y-STR testing was required because there was a small amount of DNA on the sample from the gun and that it is probable that snow could remove DNA from a surface. Fallara identified a low-level mixture of two Y-STR profiles on the DNA swabs from the 9-millimeter handgun at three locations, which was interpreted as a mixture of two males' DNA. Fallara was only able to do comparisons and statistics at one locus. She determined that defendant could not be excluded as a contributor. She testified that approximately 1 in 2 unrelated African-American males, 1 in 2 unrelated Caucasian males, and 1 in 2 unrelated Hispanic males cannot be excluded from having contributed to the mixture based on a 95% confidence limit for each population. The profile was consistent with one in every two unrelated African-American, Caucasian, and Hispanic males. D did not object to the admission of this evidence at trial and instead proceeded to cross-examine her. She testified, 'I would say that every two randomly selected people, one out of those two could not be excluded.' D was convicted and appealed. D appeals on the issue of the relevance of the evidence from Fallara.