I know there have been false arrests with wrong DNA. How often does that happen?

Answer by  Stan567 (417)

Not often. There are a lot of complaints and challenges to forensic evidence, but DNA is pretty infallible under modern testing. Early DNA testing was not as sensitive as modern testing, but an actual modern DNA match is incredibly mathematically accurate.

Answer by  tamarawilhite (17883)

Some of the false arrests were due to DNA contamination, in a girl slept with a boyfriend and then was raped, and the boyfriend was arrested for rape based on more of his DNA present than the rapist. Occasionally it was due to contamination by multiple people handling an object.

Answer by  jalucia (936)

It's hard to say because there are so many variables present with DNA. DNA errors occur regularly. Cross contamination, mislabeling and misinterpretation of results can all lead to false positives. If your DNA is in a government DNA database, you face a higher risk of being falsely linked to a crime than a person who is not.

Answer by  Binome (1975)

Real data may never be known. There's a huge backlog of people in prison who want their case DNA tested. Check out the documentary "After Innocence" to find out more.

Answer by  elynne (1153)

I believe that it happens more rarely than the media wants to say it does. The process of DNA matching is very costly and very detailed. Therefore it is given great care in the processing of the data. Thereby making the incidents of fales matching very unlikely