It didn't offend him enought while working there, yet I can almost understand his silence, the FBI would have ruin his life while employed.
I am stunned that other chemists let the FBI get away with such bogus science in courtrooms for so long.
Posted on 04/18/2002 10:47:43 PM PDT by Darkshadow
Michael Behn is serving a prison sentence in the US for a murder he maintains he did not commit.
In 1997, just 11 days before he went to trial, his defence team was notified that the FBI had evidence showing that bullets found in Behn's house were identical to those used to kill New Jersey coin dealer Robert Rose. His lawyers could not find an expert witness to dispute the bureau's testimony, and Behn got life.
The assumption that bullets found at a crime scene can be matched to those in a suspect's possession has helped convict countless murderers, robbers and armed felons in the US, Britain and elsewhere. Forensic scientists analyse lead bullets for traces of antimony, tin, arsenic, copper, bismuth, silver and cadmium.
The idea is that if two bullets have the same chemical signatures, they must have been made at the same time from the same batch of smelted lead. British firearms expert Jonathan Spencer, from the forensic services firm Keith Borer Consultants in Durham, says it is also common for this link to be made in court cases in Britain.
But New Scientist has learned that this assumption is plain wrong. An examination of detailed records held by manufacturers of the lead used to make ammunition shows it is impossible to prove that any two bullets come from the same batch.
Death row
"If you're in a court of law, you really need to do your homework, because you're putting people in jail or on death row," says Erik Randich, the forensics consultant and metallurgist based at Lawrence Livermore National Laboratory who made the discovery.
No one knows how many verdicts have rested on such evidence, and it is unclear whether the revelation would have changed the verdict against Behn. But there are now fears that the technique may have directly or indirectly led to numerous miscarriages of justice.
Randich says one FBI analyst told him that he has testified in hundreds of court cases that bullets could be matched in this way. Randich has informed the FBI of his findings, but the bureau did not answer New Scientist's requests for comment on whether it plans to change its procedures.
No one is questioning whether the rifling on a bullet can be matched to a specific gun barrel or other spent bullets, but whether a chemical analysis of a slug can pinpoint its source. Until now, the chemical bullet-matching technique had never been double-checked. So Randich and former FBI chief metallurgist Bill Tobin analysed several years of data kept by two lead smelters that supply the raw material for ammunition.
Trace elements
Smelters carefully monitor the levels of the trace elements in their lead in order to meet standards set by the battery industry, which uses most of the lead produced in the US. Lead for ammunition comes from the same batches. The manufacturers record the levels of at least 15 trace metals, including those measured by the FBI, from samples taken when smelters start and finish pouring a batch of lead into casts.
The researchers examined records for 1998 to 2000 held by Sanders Lead Company in Alabama and Gopher Resources Corporation in Minnesota. They found many instances where it was impossible, using the FBI's chemical profile standards, to distinguish between batches poured months apart. Another analysis of an earlier set of Sanders records revealed the same problem.
The researchers also found small but measurable differences in the composition of lead samples taken at the beginning and end of the same batch, probably due to oxidation of the trace elements. That means it is impossible to say whether any two bullets were made on the same day or come from the same box.
"You'll find bullets that are indistinguishable that were made months apart," says Randich, who presented his results last week to a meeting of the American Chemical Society in Orlando. Randich and Tobin, along with analytical chemist Wayne Duerfeldt at Gopher Resources and metallurgist Wade McLendon at Sanders, will also publish their findings in a future issue of the journal Forensic Science International.
Coincidental match
Tobin was never involved in the forensic testing of lead ammunition during his time at the FBI. But he became so concerned by the interpretation of the bullet data that he contacted Randich once he had retired. "It offended me as a scientist," he says.
In 1999, the FBI commissioned its own research into the validity of bullet matching. The bureau asked Alicia Carriquiry, a statistician at Iowa State University, to determine whether it was possible to give a statistical probability that two bullets came from the same source.
Her study, which she says she submitted to the FBI in May 2000, found that while it is theoretically possible to determine the likelihood of a match, the FBI did not have enough data to do it.
Carriquiry says Randich's work shows there is a high probability that a match is simply due to coincidence. Spencer agrees: "It's taken as pretty strong evidence. But it should be wrapped in a heavy caveat, and I've never seen that done in court."
© Copyright Reed Business Information Ltd.
It didn't offend him enought while working there, yet I can almost understand his silence, the FBI would have ruin his life while employed.
I am stunned that other chemists let the FBI get away with such bogus science in courtrooms for so long.
A few wrongful convictions along the way to that great public service is a small price for society to pay.
It's the usual problem. The People have the money to run a big lab and the Defence cannot afford to pay for independent tests.
No such thing as a "Mom and Pop Chemist Shop". Chemists work for large corporations,and large corporations want gooberment contracts.
Stay well - Stay safe - Stay armed - Yorktown
I would think!
No lab work was necessary, just a review of the goverment work.
The problem was no defense lawyer must have ever questioned a chemist or the bullet manufacturer, to check if the facts as stated were correct.
I do think (maybe incorrectly) that some of the statistics are skewed. The police and lab people may clear people before trial so conviction rate may be high just because mostly guilty are tired, or in bad cases, where false convictions are rampant (rampart??).
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