THE O.J. SIMPSON MURDER TRIAL

UCLA law professor Peter Arenella and Loyola University law professor Laurie Levenson offer their take on the O.J. Simpson trial. Joining them is Southwestern University law professor Karen Smith, who will rotate with other experts as the case moves forward. Today’s topic: After brief testimony from a tow-truck driver, the prosecution opened the DNA phase of its case with George Clarke questioning Cellmark Laboratory director Robin Cotton.

PETER ARENELLA

On the prosecution: “With Woody Clarke asking succinct questions that set the stage for Cotton’s mini-lectures, the jury received its first lesson in basic DNA science and testing. While Clarke may have been overly ambitious in how much information he presented to the jury, Cotton did an excellent job of using her own simpler visual aids to highlight the basic points the jury must understand to appreciate the strengths of the positive RFLP test results.”

On the defense: “The defense already has spent considerable time educating the jury about the risks of contaminated evidence and degenerated DNA. But jurors learned from Cotton that such problems will not generate RLFP test results that falsely implicate O.J. Apart from debating the merits of how light bands should be interpreted, the defense probably will rely on its conspiracy theory to explain the positive RFLP matches linking O.J. to the murders.”

LAURIE LEVENSON

On the prosecution: “Cotton brought her own three C’s to the prosecution’s case: She is clear, concise and competent. Clarke and Cotton did an excellent job of providing the jury with a DNA primer and then teasing the jurors with an X-ray that has unknown DNA results. Cotton’s testimony is critical because the jurors only will accept DNA results if they are comfortable with the science. The goal is to make DNA as simple as ABC.”

On the defense: “Perhaps sensing he had been away from the jury too long, Johnnie Cochran handled the cross-examination of the tow-truck driver. Although the driver held fast to his testimony that the Bronco door was locked when the car was towed, Cochran elicited from him that he did not see any blood in the Bronco at that time. Even before Peter Neufeld starts to attack the DNA science, Cochran wants to re-establish his bond with the jury.”

KAREN SMITH

On the prosecution: “What we saw Monday was the kind of witness preparation that exemplifies what good direct expert testimony should be: educational. The questions flowed easily and logically. Cotton, a classic expert witness, was charming and went through difficult material in a straightforward, digestible form. She was there to have a conversation with the jury and she understood that. She said you could do RFLP DNA testing in your kitchen; it was very user-friendly.”

On the defense: “What is Neufeld going to do on cross-examination? The defense has to see if there is any way to get their ‘false positive’ theory going; it stalled on them with what has been explained so far on DNA. Up to this point, the defense has enjoyed a bit of a free ride. They have been able to suggest questionable evidence collection might have led to incorrect results. But in this DNA phase that free ride will come to an end because now it’s put up or shut up.”

Compiled by HENRY WEINSTEIN / Los Angeles Times