On the Dangers and Potential Abuses of DNA Familial Searching

Advocatus Diaboli sends a story of how a high tech forensic procedure almost led investigators to the wrong person. In 1996, a young woman named Angie Dodge was assaulted and murdered in Idaho Falls, Idaho. There was a conviction in the case, but later reports claimed the wrong man was in prison, and police thought there were more than one attacker anyway. This eventually led to the re-opening of the investigation. Using DNA evidence that had been preserved from the crime scene, police used a controversial technique called familial searching to try to find a lead. This method is used when there is no direct DNA match within the available databases. Instead, it tries to identify family members of the suspect. Police found a partial match, which eventually led them to Michael Usry, a New Orleans filmmaker. They convinced a judge to provide a search warrant to extract Usry's DNA and test it against the sample. It wasn't until a month after the extraction that they told him he'd been cleared.

Comments

System worked, then?

[CrimsonAvenger]

So, they got a warrant like they're supposed to.

Then they executed the warrant, gathered a DNA sample, and tested it.

Sample came back as not matching, so they removed the suspect from their list of suspects.

So, what's the problem here? They checked out a lead (using legal methods, like a warrant), found it went nowhere, and continued the investigation into other possible leads....

Re:System worked, then?

[Anonymous Coward]

You do know that only a very small sliver of DNA is actually tested. There is a high change of collision when you are actually searching for familiar matching, you are basically searching for a birthday paradox here.

There are calculations that have shows for every DNA there are 3000 people who will match it within the USA itself.

Re:System worked, then?

[Anonymous Coward]

Why should he have been worried for a month?

Have you not been paying attention the last few years? Government enforcers -- local and three-letter -- have established that they're willing to ignore the law and evidence in favour of roughing up and incarcerating somebody -- anybody -- regardless of whether or not they're actually guilty of anything.

Re:Non Story

[Anonymous Coward]

No mistake was made. The police checked a potential suspect and cleared him.

Well, this should cause anyone using a DNA service or donating their DNA to science to think twice:

The elder Usry, who lives outside Jackson, Mississippi, said his DNA entered the equation through a project, sponsored years ago by the Mormon church, in which members gave DNA samples to the Sorenson Molecular Genealogy Foundation, a nonprofit whose forensic assets have been acquired by Ancestry.com, the world’s largest for-profit genealogy company.

What the actual fuck?

Re:All DNA Evidenceis overrated

[Half-pint HAL]

This is semen. On the body. You pretty much had to be there.