Your relative’s DNA stored online can make you a Suspect in an unsolved crime

Familial DNA privacy Warning
Familial DNA privacy

Years ago a father provided a DNA sample to a genealogy project through his Mormon church in Mississippi. Years later his son became the prime suspect in a 10 year old unsolved murder when his fathers DNA came up as a partial match with DNA found at the crime scene and his Facebook profile showed that he had a connection with the location of the crime.

What is Familial DNA?

Familial DNA is a database search that looks for partial DNA match to identify possible relatives. Familial DNA is being used by an increasing number of law enforcement agencies in an attempt to solve previously unsolved crimes.

Familial DNA is used when police have a DNA sample from a crime scene but there is no exact match on their own databases so they look for a partial match (similar DNA profile indicating a sibling, child, parent or other blood relative)..

Familial DNA searches can help solve crimes and arrest criminals that might otherwise have evaded justice. The Grim Sleeper serial killer was identified when a significant number of genetic markers matched that of a convicted felon. The Grim Sleeper serial killer was his son.

High Number of False positives

The process is far from perfect and there are some that question its value such as Erin Murphy who is a New York University law professor and the author of Inside the Cell: The Dark Side of Forensic DNA. Erin says that “Anyone who knows the science understands that there’s a high rate of false positives” and explains that searches look for DNA profiles that are similar to the perpetrators but by no means identical, a scatter-gun approach that yields many fruitless leads, and for limited benefit.

A 2014 study found from the UK found that just 17 percent of familial DNA searches “resulted in the identification of a relative of the true offender”

Searching Nongovernmental Databases

Some Police have extended searches to nongovernmental online medical and genealogy databases such as 23andme and

This results in many innocent people being identified as a suspect as happened to Michael Usry who became a suspect in a 10 year old unsolved murder case when a partial match was made through a partial match with his father who years earlier had donated a DNA sample to a genealogy project through his Mormon church in Mississippi.

He became the prime suspect in the crime when his Facebook profile showed that he had taken a trip to a location years before that was near where the crime was committed.

Michael was finally cleared after a nerve-racking 33-day wait while the DNA sample that he was required by court order to submit was checked against the sample held of file for that unsolved crime.

Familial DNA and Privacy

As the cost of rapid DNA analysis falls more and more law enforcement agencies will turn to Familial DNA searches. There needs to be guidelines and privacy safeguards.

Given that Familial DNA is already prone to giving a high number of false positives the searching of Nongovernmental Databases by law enforcement should be prohibited.

There is also the issue of privacy. When the father of Michael Usry submitted the sample years before he was not told that it might be used by law enforcement. The reality is that those who operated the database did not foresee the possibility of the database being used for a purpose it was never intended.