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Denver's DA Behind The Push For Expanding Criminal DNA Sampling

Mitch Morrissey
Mitch Morrissey (credit: CBS)

DENVER (CBS4) - It's headed for a tough fight in the Legislature, but the man behind the plan to require anyone convicted of any crime in Colorado to provide a sample of DNA says it would be a great tool for fighting crime.

Denver District Attorney Mitch Morrissey is one of the nation's foremost experts on DNA. He prosecuted the first case involving DNA in Colorado more than 20 years ago and wrote the state law that requires felons to give DNA samples. He's now pushing to broaden that law to include those convicted of misdemeanors.

Denver Democrat Rep. Dan Pabon introduced a bill that would do that last month, despite the fight the ACLU is expected to put up. Offenders would have to pay for the cose of the DNA test, but Morrissey admits there would be hefty lab costs. He says the return on the investment would be exponential, though.

"This is a science that helps us prevent crime, save lives and exonerate innocent people," Morrissey said.

New York is the only state that currently mandates DNA samples in crimes that aren't felonies. Morrissey says their results since passing the law have been remarkable.

"Since 2006 they've been taking DNA on misdemeanor petty thefts and they have solved 48 murders and 220 rape cases," he said.

"Most people know that criminals start their criminal career at the misdemeanor level," Morrissey said.

Morrissey says DNA is the gold standard of forensic science today and that cases like William Costello's provide a solid argument for expanding the DNA database.

William Costello
William Costello (credit: Denver DA)

Costello was arrested in a grocery store parking lot last July and accused of assaulting an at-risk adult (a felony). Investigators linked his DNA to three rape cases. If the assault had been a misdemeanor, there would have been no DNA taken. (Costello Case Archive)

"The most important thing to realize about this is 90 percent of the victims of crimes we solve using DNA are women and the 10 percent that are left -- the majority, about 9.5 percent, are kids," Morrissey said. "The really important part of my job is to make sure that the people that get convicted in my jurisdiction -- and it's been my whole career -- are the person who commits the crime. And DNA tells you that, and there's no better way to know that."

DNA Sample Test
DNA (credit: CBS)

About 33,000 people are convicted of misdemeanor crimes in Colorado each year.

When New York passed their bill into law they withstood a tough fight from the ACLU and other critics who said it is an invasion of privacy. Critics also questio how it would be regulated and whether it would be reliable enough.

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