On the defense: Criminal science

This just in from Philly.com: "For decades, prosecutors have relied on crime-solving techniques such as fingerprints, ballistics analysis, and eyewitness accounts to put people behind bars, even on death row. Now, in the aftermath of the stunning impact of DNA testing, many of those time-tested methods are under legal attack.

In Philadelphia, Kenneth Mapp, 35, is fighting a robbery charge filed after police concluded that a partial print lifted from a pizza-restaurant heist came from his right pinkie. His lawyer will dispute the scientific validity of fingerprint analysis at his forthcoming trial.

From Pennsylvania's death row, convicted murderer Daniel Dougherty, 51, is hoping to be freed based on his contention that "junk science" led a jury to convict him of setting a fire that killed his two sons.

And with mounting proof that eyewitness accounts are often wrong, New Jersey is examining how such evidence should be used, while a Pennsylvania committee is expected next month to make recommendations aimed at preventing wrongful convictions.

Fingerprint and firearm analyses, arson investigations, and forensic conclusions about bite marks, footprints, and hair and fiber comparisons have, in varying degrees, all been called into question. There are even growing concerns about what was once considered unassailable evidence of guilt - a confession.

"People in the criminal justice system, including judges, have a lot more skepticism than they once had," said Philadelphia Common Pleas Court Judge Benjamin Lerner, who has presided over criminal cases for more than 20 years.

The legal challenges around the country are an outgrowth of the revolutionary impact of DNA testing, which has freed 267 prisoners nationwide, including 10 in Pennsylvania and five in New Jersey, and caused four states, including New Jersey, to end the death penalty.

Eyewitness testimony was a factor in the convictions of 75 percent of those exonerated through DNA testing, according to the New York-based Innocence Project. Faulty forensic evidence contributed to 50 percent of the convictions. The project said that 25 percent of the defendants later found innocent had confessed or pleaded guilty, and that jailhouse informants were a factor in 15 percent of the overturned cases.

Despite the popularity of TV's CSI shows, many of the forensic methods used in modern crime-solving also took a hit when a National Academy of Sciences report said that all too often, forensic evidence was presented in court "without any meaningful scientific validation."

The need for improvement was "tremendous," said the 2009 report, which called for uniform standards, certification, and peer-reviewed research to ensure greater reliability. It said that in fires, for example, "rules of thumb" pointing to an accelerant being used "have been shown not to be true," and limitations of fingerprint identification may also have led to wrongful convictions.


The idea of bad forensics is nothing new to James McCloskey, the founder of Centurion Ministries in Princeton, which has won the release of 40 prisoners since 1983.
"Forensic evidence is like gold" in courtrooms, he said, and it can be extremely difficult, even impossible, to successfully challenge faulty scientific conclusions after a jury's verdict. Pennsylvania, he said, is one of the toughest states for a defendant to challenge a conviction based on new evidence.

David L. Faigman, a professor at the University of California Hastings School of the Law, said one day people would look back with dismay on all the defendants convicted of crimes based on "pseudoscience" and old-fashioned techniques.

"Our children's children . . . will say the legal system was profoundly ignorant about science," said Faigman. "We're turning a corner, but like a luxury liner, it takes a long time to change direction. And there are a lot of hurdles."

He said few states are "forward thinking," though New Jersey's decision to review eyewitness identification makes it a standout.

Law enforcement officials defend the integrity of many long-used investigative techniques. If anything, "the technology has been enhanced by advancements in science," said Upper Darby Police Superintendent Michael Chitwood, a former homicide detective in Philadelphia.

Dauphin County District Attorney Edward Marsico, president of the Pennsylvania District Attorneys Association, said he didn't buy all the National Academy of Science findings and still had faith in evidence like fingerprint and ballistic analyses.

"Are there false confessions? Sure. Are there bad eyewitness IDs? Absolutely. What's the best way to combat that? We're not sure," Marsico said.

That is precisely the dilemma facing courts ..."

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  1. Grumble number 1 - all evidence presented in court is forensic.

    This article is about scientific evidence - or at least, evidence which is presented as scientific. The problems arise because some processes which are thought to be scientific have not developed in a way which allows the levels of validation & review which we expect of modern science. There ought to be known error rates and levels of confidence available, and clearly there aren't for many older disciplines. That's not to say that this information can't be obtained, just that no-one has completed the work yet.

  2. Most stakeholders rely heavily on the "forensic" and less so on the "science." By that I mean forensics as debate and discussion -from the Latin root meaning forum. The team with the best set of storytellers wins.

    That being said, it's illustrative to enquire as to why studies haven't been done or why large governmental agencies continue to not question the validity of their own work. Training and experience - tons. Published error rates, published validity tests, etc ... not so much. That was what the NAS report was all about.

    Check on what the FBI had to say about the "science" of polygraphs during the hearings on the Employee Polygraph Protection Act. They understood clearly that polygraphs are not legit for scientific enquiry - they're not reliable, repeatable, etc - but they wanted to use them anyway as an interrogation tool for pre-employment interviews, interrogations, etc. So we get the EPPA, and the government gets an exception - state/local/federal law enforcement can still use polygraphs for pre-screening applicants. That's not science, just a very strong lobby group on the hill.

    To that end, one of the things that I am doing in my PhD work is to set up a school for media forensics - you can't address the issues if you don't have a venue.

    Thanks for reading. Stay tuned for more.


All comments and feedback appreciated!

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