ST. LOUIS — What do you tell a detective who says you are genetically related to a criminal and wants to know who you think it might be?
It is not an abstract question. Investigators may soon routinely trace suspects using their relatives' DNA – a technique that could solve more crimes but that causes critics to fear for innocent people's privacy.
Familial searching is not a new technology, but a new use of an old one. A crime lab worker scouring government databases for a match to an unknown suspect's DNA can sometimes detect a profile with enough similar traits that it might belong to a close relative.
Once police have a family in their cross hairs, they can investigate the members, or even seek samples of relatives' DNA to narrow the suspect pool.
"How can we ignore that?" asks Lt. Kevin Lawson, who supervises the St. Louis County police crime lab.
Experts say the technique could put heat on cold cases, increasing the number of hits by 40 percent. Britain, which pioneered the technique, has used it to solve several sensational crimes.
Software used in American crime labs isn't as useful for identifying relatives' DNA as in Britain, experts say. But even if it were, the U.S. is far from reaching consensus on whether the Constitution would allow authorities to probe an innocent person's genes to investigate a crime.
Many believe it could violate the Fourth Amendment's protection from unreasonable search.
The debate has roiled a few Eastern and Western states. Last month, California became the first state to publicly embrace the familial DNA search as a crime-fighting tool. Massachusetts could be next. Maryland is the only state to ban it.
But middle America has heard little about it.
"There has not been a public engagement on whether this practice would be ethically and legally sound, and we think that there should be," said Sara Huston Katsanis, a research analyst for the Genetics and Public Policy Center at Johns Hopkins University in Baltimore.
Fair to families?
Critics of familial DNA matching, including civil libertarians and defense lawyers, argue against putting whole families under suspicion.
"You need one member of your family to be a bad apple, and now your whole family's life is going to be up for examination," said Cindy Dryden, a St. Louis-based attorney with the Missouri public defender's office who has litigated several trials that hinged on DNA profiling.
St. Louis County Prosecuting Attorney Robert P. McCulloch called familial DNA searching "a great idea" and questioned the logic of its critics.
"Any sort of an investigation does the same thing," he said. "If you have a murder …"?, the first person you go to are family members."
He said it's like a red light camera that photographs the back of car, putting a whole family under suspicion for a traffic violation.
"Obviously there are much more serious issues involved, but the rationale is the same," McCulloch said. "The difference is that DNA testing will tell you who was driving the car."
The American Civil Liberties Union has criticized California's decision to go ahead with familial DNA searches.
"I understand the benefit and how it could sometimes result in something good – finding the supposed killer," said Anthony Rothert, legal director of the ACLU of Eastern Missouri. "But putting innocent people under genetic surveillance, the risk and harm is not necessarily balanced out by an occasional success at finding someone."
For years, Missouri has aggressively collected biological samples from state prisoners – and Illinois from all convicted felons, regardless of incarceration – to compare their DNA with evidence in unsolved crimes.
Missouri has collected more than 161,000 profiles of known offenders and 6,500 unknown samples from crime scenes; Illinois has more than 296,000 offender profiles and 15,000 samples from unsolved cases.
But neither state has had any public discussion about whether to search databases for the DNA of suspects' relatives.
As of now, neither state's laws address it, and a canvass of area police departments shows that only the larger ones were aware it was possible.
Waiting for courts
McCulloch said he and many other prosecutors are watching to see whether the practice survives legal tests in California and Massachusetts.
"This is brand-new, hot off the presses," said Milton Hirsch, a Miami defense attorney who lectures and writes on DNA issues, and who recently briefed an association of Missouri defense attorneys on the technique.
"What always happens, as more states start tinkering, is that a body of law develops from lawyers and judges and law professors, and even the legislatures, if we can wake them up," he said. "But the problem is we are at a juncture where science in this area is moving rapidly ahead of the law."
Until lawmakers give them more direction, workers in the Missouri Highway Patrol's statewide crime lab will, under an interim policy, notify a local police agency if a close partial DNA match is made.
If investigators are interested in the identity of the possible relative, the lab will conduct more tests. If kinship is found to be likely, the investigators will get the name.
So far, just one such notification has been made, according to Susanne Brenneke, who heads the state's Combined DNA Index System. She would not release details but said no one has been convicted.
More such "hits" are likely as the database grows, she said.
"The purpose of having these offender profiles is to help solve crimes, which is why we think we have the mandate to report out these partial matches," Brenneke said.
Although searches could point to suspects' relatives, Brenneke insisted the lab is looking only for a perfect match to an offender, using a stringent search to eliminate almost every other sample.
Missouri does conduct familial DNA searches for relatives of missing persons or unidentified remains, she said.
Lawyers for Illinois State Police are studying the technique and drafting a policy, an agency spokesman said. For now, every partial DNA match would come under close review before being used in an investigation, said Lt. Scott Compton. He would not say whether it's ever happened.
The St. Louis Police Department, whose bustling lab leads the state in matching unsolved cases to known offenders, declined to discuss familial matching. "We're not talking about this with you," said Officer Jeremy Stockmann.
Ed Postawko, chief warrant officer for the St. Louis circuit attorney's office, called it "an interesting topic" and said he was "glad there is some ongoing discussion and interest being raised in this area."
He said he didn't feel comfortable talking about how much his office has studied the technique.
Minorities a concern
Some critics say familial DNA techniques could put minorities under greater scrutiny. Blacks make up less than 12 percent of Missouri's population but more than 40 percent of its prisoners. That means a black Missourian would be far more likely than a white one to have a relative's DNA in the offender database.
But some police officials say the need to capture a violent criminal outweighs other considerations.
"If you've got a forcible rape, and the suspect is still at large, it seems important that you'd want to use every tool at your disposal," said Cole County Sheriff Greg White.
In 2006, British police used a familial DNA search to list 43 people who might be related to a serial rapist. The third door they knocked on was the rapist's sister, who had given a DNA sample in a drunken driving case. With police closing in, the suspect confessed to his father.
On the American side of the pond, police have just begun to find criminal suspects through their relatives. In 2005, Kansas police tracking a serial killer obtained a court order to analyze a pap smear from the daughter of their top suspect, Dennis Rader, without her knowledge.
The DNA match was so close that it pointed to her as being the child of the rapist who had called himself BTK – for bind, torture and kill. The link gave authorities enough evidence to arrest Rader; he immediately confessed he was BTK.
Experts say it's just a matter of time before American labs can better search DNA databases for suspects' relatives.
"And not much time – weeks, months, perhaps – before there will be a very good state of the art," said Hirsch, the Miami attorney.
If Missouri were to allow familial DNA searching – and improve its ability to do it – more people could be getting a knock on the door from police looking for the whereabouts of a relative.
Said Brenneke, of the Missouri crime lab: "Could it help solve crime? I'm sure it could."