A dozen years ago, just after Derrick Todd Lee was arrested and tied to a string of killings in south Louisiana, the state counted 12,000 DNA profiles in its database designed to help solve crimes.

Now, it has about 40 times as many.

When Lee died last month while still awaiting execution, authorities were quick to say lessons learned during the hunt for the serial killer helped create what is now one of the nation’s most expansive DNA databases, containing samples taken from anyone — including juveniles — arrested on a felony or a slew of misdemeanors.

Law enforcement officials and legislators say this large database provides a powerful tool for detectives, offering fresh leads on otherwise cold cases and helping link unknown suspects to unsolved crimes. But many civil libertarians worry the program has gone too far, harvesting DNA from potentially innocent people — those arrested but not yet convicted — in a manner that oversteps constitutional boundaries.

Perhaps it shouldn’t be a surprise that the state’s DNA policies have their roots in the Lee case. In 2002, during the frantic, massive effort to identify who was killing women in the Baton Rouge area, authorities cast a wide DNA dragnet, turning to the technology on a scale never before seen in Louisiana.

But when they put together a DNA profile showing one man likely committed three murders, it didn’t get a hit. That’s not because Lee had a clean criminal record or Louisiana had decided against collecting genetic information from criminals.

In fact, a 1997 state law required DNA profiles to be obtained from convicted offenders, but in the following years, no money was set aside to pay for that task. So, when Lee was sent to prison for a January 2000 bar beating, he wasn’t swabbed for DNA. When he was brought before a judge in March 2001 on a parole violation, again his DNA wasn’t taken.

It wasn’t until May 2003, when an investigator with the state Attorney General’s Office swabbed Lee’s cheek in his driveway, that crime lab analysts were able to link him to the murders, a list that eventually grew to seven victims.

The experience both validated the power of DNA technology to capture criminals and exposed the gaps in Louisiana’s system.

It also spurred lawmakers in 2003, about the time investigators were closing in on Lee, to dramatically broaden the state’s program to collect DNA profiles during booking. The database has grown from 12,000 profiles that year to nearly 500,000 samples now stored in the state’s computer systems.

Only six other states have entered more DNA samples in a federally managed nationwide database, according to FBI figures, and Louisiana has a dramatically higher proportion of DNA profiles in the database for its population size than any other state.

Jay Dardenne, then a state senator representing Baton Rouge and the main sponsor of the measure, said he and other lawmakers had been interested in DNA programs since the 1990s, but the Lee killings united support for the effort — which passed overwhelmingly — and helped free up funding.

“There was certainly a climate of fear in Baton Rouge at the time,” Dardenne said.

Effectiveness debated

Just how large an effect the program has on solving crimes in the state, though, is far harder to say. Alabama and South Carolina, two similarly sized Southern states, have both collected fewer profiles from arrestees and offenders than Louisiana. Yet law enforcement agencies in those states have used the databases roughly the same number of times as Louisiana authorities — and returned matches at similar rates, though Louisiana’s is slightly higher than the other two, according to FBI statistics.

Joanie Brocato, DNA manager for the Louisiana State Police Crime Lab in Baton Rouge, said that while variations in laws and policies among states make the numbers tough to compare, she believes Louisiana’s large database is an advantage.

“The larger the database is, the more likely that the person will be in the database to generate the leads,” Brocato said.

Professor Lawrence Kobilinsky, chairman of the department of sciences at John Jay College of Criminal Justice in New York City, said many other factors could affect those numbers, including differences in repeat offender rates or variations in crime rates.

“Of course, people will tell you the more individuals that you have in the database, the more effective it becomes at solving crime,” Kobilinsky said. “Maybe Louisiana has so many arrestees that aren’t going to go on and commit crimes; they were innocent in the first place. Maybe they’re casting such a wide net that they’re getting people’s profiles that aren’t really involved in crime.”

As of December, Louisiana had more arrestee profiles than any other state except California, according to FBI statistics.

Of the roughly 500,000 DNA profiles taken here, about 340,000 are from arrestees. In nearly every other state, the number of profiles from arrested people is a fraction of those from convicted offenders.

“We’re one of the few states in the country that has this progressive a collection database,” said Capt. Jim McGuane, commander of the State Police Crime Lab. “It’s the only good thing Derrick Todd Lee ever did.”

Brocato noted that Louisiana was one of the first states to allow DNA to be taken from many arrestees. Now, a majority of states collect DNA profiles from those arrested on at least some crimes. Nineteen states prohibit collecting DNA prior to conviction unless authorities get a warrant to do so.

The utility of using DNA to solve cases, including old ones that otherwise would remain unresolved, is undeniable. In January, the Baton Rouge Police Department booked a pair of known offenders — 38-year-old Leighton Hills and 39-year-old Allen G. Causey — in a 1995 attack on a woman who was raped in the back seat of a car and left unconscious and half-naked on the side of a road.

Evidence from a sexual assault examination of the victim in 1995 was matched to Hills and Causey after Baton Rouge detectives re-examined the case in October. DNA profiles for the suspects, both serving prison sentences for unrelated crimes, already were in the Combined DNA Index System, or CODIS .

Analysts process genetic material to work up a DNA profile — a unique set of markers akin to a genetic fingerprint — which is then entered into a statewide computer system that is part of CODIS, an FBI-maintained nationwide database of about 12 million DNA profiles.

The crime lab conducts a daily search that attempts to match newly entered samples to existing DNA profiles.

Too broad a net?

While DNA’s ability to convict criminals or exonerate the innocent is lauded by both sides in the criminal justice system, some skeptics wonder whether states are casting too broad a collection net.

“The question is: Do we want the government to have all these genetic samples?” said Elizabeth E. Joh, a professor of law at the University of California, Davis. “There are other ways the government can use these databases.”

Joh said advancing DNA science also means samples obtained for CODIS can yield increasingly personal information about people and their families. For example, she said, California allows searches that can lead to not only suspects themselves but also relatives of people in the database.

Critics say Louisiana’s policy of collecting DNA profiles at the moment of arrest undermines civil liberties, sparks serious privacy concerns and weakens constitutional protections against unreasonable search and seizure.

“Anyone can be arrested for anything. That’s why we have trials,” said Marjorie R. Esman, executive director of the American Civil Liberties Union of Louisiana.

A 2003 U.S. Supreme Court decision in a Maryland case upheld the practice but drew sharp criticism from the four dissenting justices. In a scathing dissent, Justice Antonin Scalia wrote, “Make no mistake about it: As an entirely predictable consequence of today’s decision, your DNA can be taken and entered into a national DNA database if you are ever arrested, rightly or wrongly, and for whatever reason.”

Unlike some other states, Louisiana retains DNA profiles of everyone arrested, even if no charges are filed or the person is acquitted. The DNA profile of someone cleared of charges is not automatically erased from CODIS in Louisiana, though it can be expunged upon request. Some states require profiles to be removed from the system if an arrestee is not convicted.

Franz Borghardt, a Baton Rouge defense attorney, said the state’s process to remove DNA profiles from the database is expensive and cumbersome.

“Is it legal? It’s legal in the sense that it’s been passed by the Legislature, but it definitely smells of Big Brother,” Borghardt said.

Every year, the number of cases submitted to crime labs across the state for DNA analysis increases. Brocato, of the State Police Crime Lab, said her lab’s caseload jumped 25 percent in 2015 from the year before, including a 70 percent rise in sexual assault kit submissions. The number of DNA swabs sent in on nonviolent property crime cases also has been rising, Brocato said.

East Baton Rouge Parish Assistant District Attorney Dana Cummings said any privacy risks are worth the trade-off.

“It’s not like it’s this top secret that unlocks the key to our existence,” she said of DNA. “We leave it everywhere.”

And the payoff for collecting it can be huge, she added.

“It’s a minor intrusion if you can solve a homicide,” Cummings said. “Even Derrick Todd Lee started off raising red flags that aren’t violent felonies.”

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