The O. J. Simpson murder trial will soon enter its most stupefying phase for the public but possibly the most important for those concerned about the complex nexus between science and law. Already coping with egotistical lawyers, overwhelming press coverage and frequent bomb scares in court, Judge Lance A. Ito now has the intellectually demanding task of riding herd on competing hired experts who are likely to offer wildly contrasting views on the validity of DNA testing. It is worth noting that the defense's DNA consultant, Edward Blake, worked for the \o7 prosecution\f7 in a Virginia case in which DNA results sent a serial killer to the electric chair and the Simpson prosecution laboratory, Cellmark, worked for the \o7 defense\f7 in that case. So it goes.

Ito's task is to let in only the best science and avoid asking a jury of laymen to judge the fine points of "polymerase chain reaction" versus "restriction fragment length polymorphism." His task is made harder by the unsettled nature of California law on these matters. About two dozen other states now routinely admit DNA "fingerprinting" as reliable evidence. But it was only last month that the California Supreme Court agreed to resolve contradictory appeals rulings from lower courts. Scientific developments in this and other areas of forensics are moving so fast that the state Supreme Court or the Legislature must devise a better way to introduce scientific evidence or our courts will lag badly. Oftentimes lawyers are arguing issues long after they have been mostly resolved by scientists.

For tactical reasons, the defense at first waived its right to challenge the admissibility of DNA evidence. Now it wants Ito to allow it to assault the very validity of DNA science before the jury. In the absence of clear-cut law, Ito must separate the scientific wheat from the chaff, limiting cross-examination in certain instances. Simpson's lawyers indeed should have the right to challenge the quality of evidence gathering and blood testing. But to also challenge the basic science involved? Science is never 100% certain. There is always debate among scientists, but that does not mean a test is thus unreliable.