CROSS-EXAMINATION OF DNA EXPERT

CROSS-EXAMINATION OF DNA EXPERT

For my Comprehensive Trial Advocacy course, Seattle University law students attend a day in trial and report on what they observed because that is a good way to learn the realities of trial practice. It is gratifying to read the students’ reports and to learn how being in the courtroom can be such a rewarding learning experience for them. 

Student Adam Brenneman attended a murder trial involving DNA evidence. The defendant Emanuel Fair was charged with murder in the first degree with sexual motivation. The defendant was at a party the night victim Arpana Jinaga was killed and was a friend of a woman who lived downstairs from victim. When Jinga’s body was discovered in the apartment, she was naked and her body was soaked in bleach and motor oil apparently used to obliterate any trace of DNA evidence. Police gathered items from the scene that the state crime lab could analyze.

The recovered DNA samples were degraded, mixed samples. The Washington State Crime Laboratory concluded that the blood on the victim’s robe was 1000 times more likely to contain the defendant’s DNA. However, TrueAllele, a software program, which relies on sophisticated algorithms to analyze DNA mixtures, determined that same blood was 56.8 million times more likely to include Fair’s DNA.

Adam Brenneman arrived in King County Superior Court courtroom in time to observe the cross-examination of Mark Perlin, CEO of Cybergenetics, the company that developed TrueAllele. The following are the student’s reflections on the cross-examination of Mr. Perlin.

CROSS-EXAMINATION OF DNA EXPERT

By Adam Brenneman

Mr. Perlin, an expert witness, is the owner of a DNA coding software company, TrueAllele.

During the portion of the cross examination observed, the defense was attempting to impeach and discredit Mr. Perlin by 1) challenging the process of the software, 2) pointing out the subjective portion of the process of the DNA coding using the software, 3) addressing inconsistent results between different runs of Mr. Perlin’s software, 4) challenging the result of Mr. Perlin’s software in relation to other DNA coding software.  Subsequent research outside the courtroom indicates that this case is the first case in Washington State in which software that analyzes DNA has been used by the prosecution; this type of software is also being used in other state for the same purpose.  Previously, such software has only been used to exonerate defendants in Washington State.

In addition to attacking the software itself, defense counsel also attempted to impeach Mr. Perlin using his Sound Cloud social media page, on which he posted personally written songs about a variety of topics including DNA coding and crime laboratory personnel.  The defense counsel read out loud verses from two the songs.  Defense counsel slightly misquoted the songs, these errors quickly corrected by the witness.  The mistake and quick response by the witness made the witness appear very intelligent and the defense counsel less so.  It was unclear how this played with the jury, but one has to assume if the effort is to discredit the designer of software that anytime you make the software designer (Perlin) look more intelligent, it is a bad result.

            The cross was very technical and defense counsel included a number of technical charts in a PowerPoint deck.  The charts were very difficult to read on the projector screen.  This required the witness to stand up and walk to the projector screen.  As noted below in relation to the federal courtroom, the superior court was very outdated. (Mr. Brenneman had also observed a trial in Federal Court and written a report on that experience).

            Defense counsel also allowed the expert to make extra statements outside the questions asked and generally did a poor job locking down the witness, who if he did not have the upper hand certainly was not being controlled by the attorney.

PostScript

The trial ended in a hung jury. And, the King County Prosecutor’s Office was considering whether or not to retry the case.

For more on the case, read this article in the Seattle Weekly.