THE O.J. SIMPSON MURDER TRIAL

UCLA law professor Peter Arenella and Loyola Law School professor Laurie Levenson offer their take on the Simpson trial. Joining them is former Los Angeles Dist. Atty. Ira Reiner, who will rotate with other experts as the case moves forward. Today’s topic: The LAPD’s crime lab is lambasted as a cesspool of contamination by defense expert John Gerdes.

PETER ARENELLA

On the defense: “Did the lab that processed the evidence generating DNA results do anything right? Not much, Gerdes said: The risk of cross-contamination is so high the lab should be closed. Worse, his analysis suggests that cross-contamination occurred, undermining findings of O.J.’s blood at Bundy and Ronald Goldman’s blood in the Bronco. If jurors give credence to Gerdes, they may reject all DNA evidence coming from such a ‘cesspool of contamination.’ ”

On the prosecution: “We have come to one of the defining moments of this trial: the viability of DNA evidence processed by an underfunded police forensic lab. Testing of dirty, unknown and often minuscule evidence samples carries a higher error risk than testing of clean, known and large samples performed at clinical labs. Woody Clarke’s cross must persuade jurors that a defense hired gun has exaggerated the risks and show that they were not realized here.”

LAURIE LEVENSON

On the defense: “Barry Scheck to the rescue. If he and Gerdes are right, the LAPD crime lab is more contaminated than Chernobyl and should suffer the same fate--total shutdown. Using impressive charts, Gerdes explained how sloppy procedures at the lab and by criminalists at the murder scene jeopardize the integrity of the DNA tests. The contamination theory is a major theme of the defense, and so far it is faring better than their conspiracy claim.”

On the prosecution: “It was a long day. Chart after chart, Gerdes described mistakes in LAPD’s handling of DNA evidence. Clarke will have his work cut out for him on cross. Not only is the result of this case at stake, but others whose evidence was processed by the LAPD. But all is not hopeless. Gerdes focused mainly on PCR, not RFLP, and Clarke might ask what the chances are--even assuming random contamination--that all the DNA results would implicate O.J.”

IRA REINER

On the defense: “The potential impact of Gerdes’ testimony can hardly be exaggerated. If the jury buys his view that the LAPD lab is the most contamination prone he’s ever seen and that it should be shut down, then the reliability of the DNA evidence is severely compromised. And since the case rests entirely on DNA evidence, the case can fall. Gerdes was a very effective witness and Scheck was extremely good, armed with the best charts they’ve had so far.”

On the prosecution: “The prosecution will have to show that claims of contamination at the lab are overstated. More importantly, they have to drive home the point that potential contamination doesn’t necessarily mean actual contamination. And they have to remind jurors that not every item of DNA evidence is covered by this witness. The problem is at a certain point a critical mass of doubt can set in and jurors may decide not to rely on any scientific evidence.”

Compiled by HENRY WEINSTEIN / Los Angeles Times