In Louisiana, debate over a DNA dragnet

Shannon Kohler doesn't even drive a white pickup truck. Yet police singled him out anyway, in one of America's largest DNA dragnets to date.

Authorities say sightings of a white pickup truck, along with DNA evidence, connect the brutal murders of four women found since September 2001 along Louisiana's back roads - and could be tied to a fifth murder, a woman nabbed on Christmas Eve from a Subway parking lot across the Mississippi River from here.

Mr. Kohler, who drives a wrecked Dodge sedan with a red stripe and has phone records proving he was home when the murders occurred, is not a suspect. Police targeted him on the basis of anonymous tips, an old burglary conviction, and the fact that he'd once worked on a street where the first victim's cellphone was found. But his swift protest against the test - a cheek swab - and a clerical slip in the court record that made his name public, have put him at the center of a larger feud over privacy, DNA dragnets, and an expanding genetic database that, critics fear, could become a genomic version of Big Brother.

The request for DNA, says Mr. Kohler, is "a Fourth Amendment violation" - a breach of his protection against unreasonable search and seizure.

But to local police, it's a desperate strategy in a puzzling case: a serial killer who chooses victims with no clear regard for age, race, or habits. In Louisiana, nearly 1,000 men have been tested for a DNA match - mostly on the basis of anonymous tips - and close to 800 have been cleared. Because time is critical, says West Baton Rouge chief deputy Mike Cazes, most have willingly complied. "Anybody that's been approached ..., and [the officer] explains why - most of them say, 'Sure, I'd be happy to.' " In light of such cooperation, those who hesitate - as did Kohler and 14 others - draw swift notice. "A court order would be issued immediately," says Mr. Cazes, "and they would be swabbed."

Critics fear such sweeps could lead to coercion, as police persuade vast numbers to take these tests. That in turn, creates new quandaries: the possibility of harassing the innocent, and the potential to violate suspects' rights against search and seizure.

Some experts fear that, with DNA forensic databanks now authorized nationwide, practices for evidence collection are evolving in a vacuum, with little precedent or supervision. Should the government keep on file the DNA of the innocent? Could that "evidence" come back to haunt them in future (or prior) crimes? And even beyond DNA's criminal applications, could employers, or others, access genetic profiles and weigh them in hiring decisions, steering clear of employees with medical liabilities?

"A tremendous change is afoot in criminal justice," says Philip Reilly, president and CEO of Interleukin Genetics. "It is loaded with opportunities and fraught with problems."

Indeed, 50 years after James Watson and Francis Crick discovered the double helix, DNA is transforming criminal investigations, solving such crimes as burglary and sexual assault, and linking deaths in far-flung jurisdictions. Larger DNA dragnets have been conducted in Britain and Germany. But in the US, where dragnets have swept through a Maryland hospital, a Massachusetts nursing home, and the Miami suburbs, samplings have been more controversial.

"This is leading to hit-or-miss justice for those wrongfully convicted," says Dr. Reilly, creating "pressing questions for law enforcement, the criminal justice system, and society as a whole."

But Paul Ferrara, director of Virginia's forensic science division, says genomic databanks become particularly effective when authorities have the wrong suspect - or no suspect. Several of the 13 Illinois death-row inmates freed last month had been exonerated through DNA. "The ability of this technology to assist investigators is remarkable," Dr. Ferrara says. "And we've only scratched the surface."

Now, lawmakers in states across the country are struggling to keep up with advancements in sampling and analysis, as well as with such issues as the admissibility of DNA evidence, changes in the statutes of limitation on certain crimes, and the constitutionality of DNA databases.

The national CODIS database was first created in 1989, and all states now require at least some convicts to provide DNA samples for profiling. Some databases contain only profiles from convicted murderers and sex offenders. Others go further, and the push is on to include sex-related misdemeanors. In 2000, the federal government began requiring certain federal or military offenders to provide DNA samples for the national criminal database.

As the database grows, advocates say it becomes a more powerful tool for law enforcement - and a bigger concern for critics such as the American Civil Liberties Union of Louisiana, which holds that "the samples collected implicate privacy concerns under the Fourth Amendment," according to executive director Joe Cook.

Later uses in unrelated criminal investigations are one concern, says Mr. Cook. Another question is whether the searches are consensual - and whether initial refusals, like Kohler's, are wrongly construed as probable cause, the cries of him who doth protest too much.

Kohler is talking to a lawyer about legal action to keep his DNA "fingerprint" from becoming part of any database. And in the end, it may be more traditional detective work that solves the case: Authorities say a tennis-shoe print from the scene of the most recent crime could be a crucial clue. A security camera reportedly caught a glimpse of the attacker's head, and a tip line has drawn 1,200 calls. Meanwhile, though, the dragnet goes on.