Denver District Attorney Mitch Morrissey is psyched. For the past several years, he's been working with colleagues in the Denver Police Department's crime lab, among others, to prove the efficacy of a method able to connect DNA not in law-enforcement databases to samples from family members of the scofflaw that are. And the experiment just paid off with the arrest and conviction of one Luis Jaimes-Tinajero, 21.
Jaimes-Tinajero didn't exactly commit the crime of the century: He broke into a couple of cars, cutting himself in the process -- and the blood he spilled scored a family match, leading to his arrest. But Morrissey is more interested in the potential for the technology than the fact that Jaimes-Tinajero received a sentence of two years probation in September. "This tool could be used to help us solve a serial murder case, or find a serial sex offender loose in the community, where you have a DNA profile that doesn't match anybody in the database."
Does the technology raise privacy concerns? Not in Morrissey's view.
"The Fourth Amendment deals with search and seizure," Morrissey says. "And, if you think about this, what you're taking is evidence that's been left at the crime scene by the perpetrator. And there's no constitutional expectation of privacy in that DNA. It's been abandoned, and we're running it against the DNA of somebody else whose sample we obtained legally.
"In order to be able to claim a Fourth Amendment violation, you have to be able to claim that something was searched where they had an expectation of privacy," he continues. "Well, you don't have an expectation of privacy for your brother's or your father's or your son's DNA. That's personal to them. It's just being used to search against somebody else's DNA, so that we can get a lead to catch the real person."
At the same time, Morrissey concedes that some ethical issues could crop up. "You have to be careful once you start the post-familial-search investigation. You need to make sure you don't violate anybody's rights. If you turn up something where you have people who think they're brothers and they're really not, for example, that wouldn't be relevant to your investigation. That's why the state wrote up a policy that we can follow going forward."
The procedure calls for "running a secondary DNA test," he goes on. "If we've got a male-to-male familial match, we run a Y-chromosome test. If people don't have the same Y-chromosome type, they're not related -- and we're not interested. That's the end of the lead."
If, on the other hand, there's a match, "we would start a conventional investigation," he says. "That can be done through computer records, old contacts in the penitentiary, probation records on an individual. You create a family tree and then say, 'Okay, we're looking for a son. How many boys does this guy have?' Well, say there's three, but two of them were in jail. That leaves one. So we find out, does he owe a DNA sample to the state? Is he somebody we haven't gotten around to getting one from? Or do we have enough evidence to get a court order?" In the case of Jaimes-Tinajero, authorities did, although the suspect ultimately provided a DNA sample voluntarily.
Morrissey emphasizes that "we did everything by the book" -- one originally written by law enforcers in the United Kingdom, where Morrissey staffers traveled in 2006 during the early stages of exploring the concept. They also took a trip to California, with the idea of "getting larger agencies, and agencies with more access to the larger databases in this country, interested in at least researching the idea." He's hoping the latest success will fuel more progress -- and while using the approach might not make a lot of sense on minor violations, he feels it could be cost-effective when it comes to more serious offenses.
"You just have to pay somebody to run the software, which takes about half a day," he says. "And if you're already in the run-down-every-lead model, it could save you a lot of money. If the police are spending a lot of resources trying to catch a serial predator, this gives them potential suspects."
That was the plan this month. "We were slated to go to Wisconsin to help them catch a serial murder who'd been raping and killing women for the past couple of decades," Morrissey notes. "They had a DNA profile, and they'd already used it to exonerate an innocent man. We were going to go out there to see if we could get some information that might lead to him. But they caught him two weeks beforehand -- thanks to a toothbrush..."
Where to next? Morrissey's got some ideas.
"I know, for instance, that there are some things happening in Texas. A serial rapist has been working in Houston, and they had a recent exoneration in a cold case -- they exonerated two men because the DNA didn't match DNA found on two girls in a quadruple homicide. And they have a serial rapist of elderly women in southern Texas. I'd love to go down there to help them out on any of those things."
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In the meantime, Morrissey's crew is generating "a paper for peer-review publication in a scientific journal, so that we can show this actually works."
At this point, investigators have found that "there's a DNA hit on a real person about 40 percent of the time," Morrissey says. "And I think that's lower than it needs to be. I think this technique could raise that 40 percent to 60 percent or higher."
If that happens, cops will owe a debt of gratitude to Luis Jaimes-Tinajero, convicted petty thief.