THE O.J. SIMPSON MURDER TRIAL

UCLA law professor Peter Arenella and Loyola University law professor Laurie Levenson offer their take on the Simpson trial. Joining them is Los Angeles defense attorney Gerald L. Chaleff, who will rotate with other experts as the case moves forward. Today’s topic: Chapter 2 in the DNA primer.

PETER ARENELLA

On the prosecution: “Too much foreplay. George Clarke and Robin Cotton must educate the jury about the basics of DNA science and testing procedures so that the jurors can appreciate the significance and reliability of Cellmark’s test results. But too much technical material unconnected to the bottom line may lead jurors to tune out because of information overload. To motivate jurors to do the hard mental lifting ahead, they need to hear some test results immediately.”

On the defense: “The defense cannot be happy with Cotton’s testimony so far. She is an unusual expert witness because of her ability to articulate technical concepts with common-sense examples and great clarity. Nor can the defense be pleased by Clarke’s constant references to defense expert Edward Blake’s observation of Cellmark’s testing procedures. Jurors may believe that Blake’s failure to testify for the defense confirms the test results’ reliability.”

LAURIE LEVENSON

On the prosecution: “It’s time for the results. Though Clarke and Cotton handled the examination in a very professional manner, some of the detailed presentation may have gone over the jurors’ heads. Without a degree in molecular biology, DNA can be a challenging subject for any court-watcher. Now that the prosecutors have jumped through the foundational hoops, they’ve earned the right to present their most important evidence--the actual test results.”

On the defense: “Why was O.J. smiling? Even though the defense threw a couple of minor roadblocks in Clarke’s path, they must know that the prosecution is about to present some of its most damaging evidence. Peter Neufeld’s attack plan seems to focus on statistical probabilities, but he’ll undoubtedly return to the contamination and conspiracy theories. As Cotton admitted, her precautions only extend to her lab and not into the LAPD evidence room.”

GERALD L. CHALEFF

On the prosecution: “Clarke effectively used an excellent witness to complete the jury’s education, hoping to instill a belief in the absolute accuracy of DNA testing. He also attacked a central tenet of the defense’s contamination theory by presenting testimony showing that DNA cannot be so degraded that it identifies the wrong person. As icing on the cake, he informed the jury that the defense experts visited the Cotton’s Cellmark lab and cut the DNA samples.”

On the defense: “Like everyone else, the defense still is waiting to hear the prosecution’s testimony concerning the DNA results. When it does, the defense must address the issue of their own experts’ presence in the Cellmark lab. If they fail to put those experts on the stand, it will undermine any attack they mount on the DNA test results. It also will be interesting to see whether the defense attacks the basic DNA science or simply Cellmark’s competence.”

Compiled by TIM RUTTEN / Los Angeles Times