Forensic Science often isn't/Stop thinking CSI is real.

Seventh Circuit grants immunity to bite mark ‘experts’ who put innocent man in prison for 23 years - The Washington Post: "Last month, the U.S. Court of Appeals for the Seventh Circuit granted qualified immunity to Lowell Thomas Johnson and Raymond Rawson, the two bite mark specialists whose testimony helped convict Robert Lee Stinson of raping and murdering an elderly Wisconsin woman in 1984. Stinson spent 23 years in prison before DNA testing exonerated him in 2009. Further testing implicated a man named Moses Price, who then confessed to the crime. The only real evidence against Stinson was the testimony of Johnson and Rawson, who claimed they could match bite marks on the victim’s body to Stinson, to the exclusion of everyone else. Johnson claimed that the marks on the woman “had to have been made by teeth identical in all of these characteristics” to Stinson’s. Rawson claimed the marks matched Stinson’s teeth “to a reasonable degree of scientific certainty.”

I wrote a bit about Stinson’s case in my series on bite mark evidence that ran in February. The particularly remarkable thing about Stinson’s case is that in his appeal, he challenged the validity of bite mark analysis, claiming that there’s no scientific research to support its claims. In 1986, the Wisconsin Supreme Court conceded in a footnote that without the bite mark evidence, the state’s case against Stinson “may not have been sufficient to convict him.” But the court not only rejected Stinson’s appeal; the justices also spent a dozen paragraphs meticulously explaining why bite mark evidence is sound."

...this is almost entirely due what you might call a judicial echo chamber that began with the 1975 case Marx v. California. In that case, a California appeals court admitted testimony from bite mark analysts who had done their analysis six weeks after the murder victim had been autopsied, embalmed and buried. Even so, the court did not perform an analysis of the scientific validity of the evidence. Indeed, it conceded that there was no scientific evidence to analyze. Instead, the California court simply stated that the trial judge had eyeballed the evidence and found it persuasive. To overrule the trial judge, the court concluded, “would be to abandon common sense.” As one critic of forensic analysis put it, Marx became a “global warrant” for bite mark evidence across the country...

The problem is that this case didn’t exist in a vacuum. The courts allowed fraudulent experts to put a man in prison. But the courts now say that because the courts made that mistake, the man who was wrongly imprisoned can’t sue those experts...

It took more than three decades, but over the past several years, actual scientists have finally started testing the claims of bite mark analysts. And as we’ve pointed out on several occasions here at The Watch, those scientists are showing that bite mark analysis is a fraudulent field. Even the ABFO’s own effort to show that its accredited analysts used sound science backfired and showed precisely the opposite. When given photos of marks on human skin, the analysts couldn’t even come to a consensus on whether marks were made by human teeth. Last July, a senior-level science adviser to President Obama said that bite mark evidence should be “eradicated” from the courtroom. The same month, Judge Gary Feinerman of the United States District Court for the Northern District of Illinois found that “There appears to be little, if any, scientifically valid data to support the accuracy of bite mark comparison, and the data that does exist is damning.” He went on to call bite mark analysis “transparently fraudulent” and compared the field to astrology."