FBI Says Better DNA Tests Offer Certain Identification

DNA evidence, used for years to bolster criminal cases, now is technologically advanced enough to specifically identify murderers, rapists and other criminals, the FBI said Wednesday.

The improvement in technology has spawned a change in FBI policy that has already helped convict a Wisconsin rapist, even though he had four alibi witnesses that distanced him from the crime, FBI officials said at a news conference.

“Up to now we’ve been able to exclude an individual wrongly associated with a crime” by using DNA evidence, said Dr. Bruce Budowle of the FBI’s Forensic Science and Training Center. “We can now assert that this [genetic] profile, from this evidence, could come from only one individual.”

The new FBI policy, which took effect Oct. 1, allows FBI experts to testify definitively that a certain DNA sample is traceable to a certain suspect, rather than stating the mathematical probability that this is so, or stating that the individual cannot be excluded as a suspect.

Six areas along the DNA molecule in the crime sample, instead of the previous four areas, are examined.

Jenifer L. Smith, head of the FBI’s DNA unit, said DNA science now is so certain of matching a single individual to a blood or semen sample that the odds can be 1 in a trillion that the specimen could have come from anybody else. Earth’s population is about 5.8 billion.

In a news conference conducted with great fanfare, FBI laboratory director Donald M. Kerr said that the new techniques constitute “a major breakthrough.”

But the announcement had as much spin as substance. Officials admitted the new process is almost identical to the laboratory and statistical analysis used on specimens from the O.J. Simpson trial in Los Angeles. DNA samples from that 1995 murder trial were analyzed at Cellmark, a private lab in Maryland. Simpson was acquitted in the murders of two people, including his ex-wife.

Simpson’s defense team convinced a jury that the DNA evidence had been tainted.

The FBI lab has been blasted in recent months by Congress and by the Justice Department’s inspector general for sloppy, flawed scientific work and for presenting inaccurate testimony in major cases.