A swab of your cheek or a tube of your saliva is all it takes to uncover your DNA heritage — but it can also help detectives who are scouting for clues about criminals.
With the popularity of companies like 23andMe, AncestryDNA and My Heritage DNA, forensic genealogy has become a powerful tool in fighting crime.
According to researchers, more than 60 percent of Americans who have some European ancestry can be identified using DNA databases — even if they have not submitted their own DNA.
“If a family member puts their DNA into one of these family search databases by DNA, law enforcement can make a family connection and further their investigation,” retired Metropolitan Police Department detective Rodney Parks said.
The technique got national attention last year after the notorious Golden State Killer was captured in California, nearly 40 years after his reign of terror began.
DNA from a distant relative on a public genealogy website called GEDmatch proved to be the big break police needed to arrest Joseph DeAngelo — and officers didn't need a warrant to tap into it.
“There are no specific parameters for going into those sort of databases. The companies themselves have certain restrictions,” Parks said.
As home DNA kits become more popular, the databases are growing larger, and giving police a better chance at making an arrest.
“Any time you smoke a cigarette, or you drink from a cup or you eat with a utensil. Those all are potentially sources of your DNA,” said Dr. Jenifer Smith, the director of D.C.'s Department of Forensic Sciences.
With decades of past experience working at the FBI, she's seen the science evolve.
“In that day and age, we needed a stain about the size of a nickel. Now, we can get DNA and amplify it or copy it from very very small stains. Even stains you can't see," Smith said.
Smith says with time, the D.C. lab's technology will likely become more precise.
“In the future, we're going to be able to perhaps even predict what a person's hair color is or what their eye color is. We might be able to determine what their ancestry is,” Smith said.
In 2016, more than 62 percent of criminal cases in D.C. were resolved through DNA found in their internal database.
Critics say the practice raises significant questions about privacy, but for those in law enforcement, the public safety aspect outweighs those concerns.
“Apprehending criminals, to me, is the highest priority to consider,” Parks said. “If it's working within the law and it gets the case solved, then all the better.”
By taking any genetic tests you're essentially giving up the rights to your DNA and potentially becoming a genetic informant for officers.
Maryland and D.C. are the only two jurisdictions in the country that ban police from using familial DNA searches to solve crimes.
Maryland Del. Charles Sydnor recently introduced a bill that would prohibit officers from searching public genealogy databases to identify offenders.
All this week News4 is looking into home DNA test kits. Watch News4 at 5 and 6 p.m. on Wednesday for a closer look at what they can reveal about your health.