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The Smoking Gene

What rapid DNA testing means for cops and criminals

One night this January, on a darkened stretch of highway near Tucson, Arizona, James Waltermire starts his workday close to midnight. In the flashing pulse of emergency lights, he scrambles down an embankment strewn with car parts and beer bottles to an upside-down red Ford Escape. A detective with Arizona’s Department of Public Safety, Waltermire, who has short hair and a boyish smile, is called only to the worst wrecks; the dead teenage girl half ejected from the passenger window makes this a bad one, and the beer bottles point toward a crime.

The other two occupants were thrown clear of the car during its three or four cartwheeling flips. A man flew out first and landed in the grass 75 feet away, badly injured but alive. Another woman was found sitting in the dirt near the car, clutching a Chihuahua; Waltermire suspects she was driving, and therefore responsible for the death. While she’s being treated at the hospital, Waltermire dons a mask and rubber gloves and shimmies across the hood of the now-righted car and through its missing windshield.

He swabs spattered blood from the dashboard, the headliner above the steering wheel, the visor, and a towel on the driver’s seat. He seals the swabs in small evidence boxes and heads north, to the department’s main crime lab in Phoenix and a tiny, windowless room that houses a modern forensic wonder: a new, printer-size machine that can generate a genetic profile in 90 minutes.

Once he’s settled in the lab, he slips the swabs into individual plastic cartridges and loads another with a blood sample taken from the woman at the hospital. He inserts the cartridges into the RapidHIT 200 and pokes the start button. The machine whirs.

A traditional dna test would require the services of forensic scientists in the laboratories upstairs and take at least 48 hours. But, practically, Waltermire wouldn’t see results for six months to two years. Arizona’s crime lab services 296 police agencies and tribal jurisdictions. While vehicular homicide is serious, priority usually goes to murders, rapes, and aggravated assaults, and Arizona already has a backlog of several thousand cases awaiting genetic testing.

All of the state’s 140 forensic scientists have natural-sciences degrees; a third hold master’s degrees or Ph.D.s. And a dna analyst needs a year of on-the-job training. By comparison, Waltermire, who’s been in law enforcement for nearly half of his 41 years, took a weeklong class last spring.

Back in his office, where he’s waiting out the 90 minutes, Waltermire rattles off the potential benefits of the new technology: time saved not investigating dead ends; more plea bargains, which can prevent drawn-out court cases; a smaller dna backlog. “If it takes months to get your results, how many other crimes would have been committed?” he says. “Instead of them fleeing, or running around on the outside, they’re sitting in jail where they belong.”

He tells me about a case last summer in Goodyear, a Phoenix suburb. A woman stepped from her shower to find a man in her bedroom masturbating. She punched the intruder in the groin, and he fled. Police swabbed semen from the woman’s hand, but the case was too low-priority for immediate attention at the crime lab. After ten days, and still with no leads, a Goodyear detective remembered that Arizona had just become the first state to adopt rapid dna testing.

He brought the sample to the crime lab in Phoenix, where one of Waltermire’s colleagues processed it. The RapidHIT, which is made by Pleasanton, California–based IntegenX, one of several companies that produce such machines, generated a profile, and a state database of 300,000 dna profiles from convicted felons and arrestees spit out a name: Christian Morgan, a 21-year-old who lived nearby and was suspected in similar cases.

This quick turnaround tantalizes law enforcement. The Pentagon envisions all-in-one dna machines identifying terrorists on distant battlefields. Homeland Security will use them to confirm immigrants’ and refugees’ identities, or to verify that children are related to adults accompanying them across the border. The F​BI, which started the national dna collection system in the early 1990s, wants them in police stations nationwide.

This ubiquity would bring certain risks. Though the technology isn’t cheap — the machine costs $250,000, and each five-sample cartridge runs $1,750 — civil-liberty advocates fear its convenience will entice cops to sidestep the Fourth Amendment. Many states already allow police to take dna samples upon arrest, not just conviction. While rapid-generated profiles can’t yet be loaded into the national dna database, which is tightly regulated, states maintain their own inventories, which include samples from unsolved crimes.

In what’s popularly known as “the CSI effect,” today’s prosecutors can be loath to take a case without dna support. They ask for tests on everything: urine on a light pole, drugs pulled directly from a suspect’s pocket, a $20 bill, never mind how many dozens probably touched it. “The people who watch these shows are the same people who serve on juries, who are judges,” says Detective Mike Thomas, one of Waltermire’s colleagues. “They expect the same level of investigation, which is just not practical or possible in most cases.”

Yet rapid dna machines get police much closer to that tidy TV promise of same-day crime solving, which is what Waltermire is hoping for with his car-crash investigation. He’s already been on the clock 14 hours, and he has a stack of other cases waiting on his desk.

Back in the RapidHIT room, which smells of marijuana from the evidence locker next door, the machine hums like an overworked refrigerator, ticking down its final seconds. Each sample appears on the touch screen as a series of parallel peaks, called short tandem repeats, that reflect the uniqueness in our genetic code. Waltermire traces his left index finger across the screen and jots down numbers on scrap paper. He raises an eyebrow, grunts, and sighs. The samples he gathered from the car are all from the same person, but not the driver. The passenger had bounced around the interior, leaving her blood everywhere.

“It doesn’t give us the quick, easy answer we were hoping for,” Wal­termire says. “A slam dunk, that would have been great.”

In coming days, forensic scientists will go over the truck and find a piece of pink sweater near the steering wheel that matches the suspect’s clothing, which together with other evidence is enough to place her behind the wheel and charge her with homicide and driving drunk.

But the test confirms a sad fact of Waltermire’s investigation. Though the suspect’s dna sample doesn’t match the four taken from the car, it is very similar to them. Our parents supply our genetic code, and on the spiky graphs, this much was clear: The driver killed her 16-year-old daughter.