BUFFALO, N.Y. (AP) - When a 60-year-old man spat on the sidewalk, his DNA became as public as if he had been advertising it across his chest.
Police officers secretly following Leon Chatt last August collected the saliva - loaded with Chatt's unique genetic makeup - to compare with DNA evidence from the scene of an old murder they believed he'd committed.
On Feb. 1, Chatt was charged in one of Buffalo's oldest unsolved cases, the 1974 rape and stabbing of his wife's stepsister, Barbara Lloyd.
While secretly collecting a suspect's DNA may be an unorthodox approach to solving crimes, prosecutors say it crosses no legal boundaries - that when someone leaves their DNA in a public place via flakes of skin, strands of hair or saliva, for example, they give up any expectation of privacy.
But the practice has raised questions from Washington state to Florida, where similar collections are under scrutiny.
"If we felt it wasn't proper and we didn't have a strong legal foundation, we wouldn't have done it," Erie County District Attorney Frank Clark said, discussing another recent case involving secretly obtained DNA.
In that case, the smoking gun was tableware the suspect used during a night out with his wife. Undercover investigators had waited out Altemio Sanchez at the bar of a Buffalo restaurant one evening and moved in on his water glass and utensils after he'd gone.
Two days later, the 49-year-old factory worker and father of two was charged with being the elusive "Bike Path Rapist" believed responsible for the deaths of three women and rape of numerous others from the early 1980s through 2006.
Lawyers for Sanchez and Chatt say both men continue to profess their innocence. Both have pleaded not guilty to charges of second-degree murder and their cases are pending in the courts.
DNA, which is unique to every person, has become a cold case squad's best friend. Investigators can re-examine things like hair, blood, semen and carpet fibers from decades-old crime scenes and cross-reference the DNA with ever expanding databases kept by law enforcement.
"It's one of the greatest tools that law enforcement has today," said Dennis Richards, the Buffalo Police Department's chief of detectives.
New York state last year underscored the value of DNA by tripling, to about 46 percent, the number of people convicted of crimes who must submit a sample to the state's database.
To catch up on a backlog, Erie County in January conducted an unusual two-day DNA "blitz." Hundreds of convicts who "owed" a sample were summoned to a downtown courthouse, where an assembly line of sorts was set up to swab their mouths.
But it is the so-called "abandoned" DNA like that collected from Sanchez and Chatt - and suspects elsewhere arrested based on discarded cigarettes or chewing gum - that concerns people like Elizabeth Joh. The University of California law professor believes it is time legislators consider regulating such collections out of concerns for privacy.
Right now, police rely on abandoned DNA when they lack enough evidence to obtain a court-ordered sample.
"If we look at this kind of evidence as abandoned, then it really permits the police to collect DNA from anyone - not just cold case issues - from anyone at any time and really for no good reason or any reason at all," Joh said.
"That's something that maybe sounds like a science fiction scenario - police running after people trying to get their DNA," she said, "but we really don't know where this could lead."
Asked whether there should be boundaries on such collections, Richards said, "That's one for the lawyers to argue in a court of law."
Chatt's attorney, John Jordan, said he would "absolutely" challenge the DNA evidence in his client's case in court but declined to elaborate.
Prosecutors tend to view abandoned DNA as akin to trash, which courts have upheld as fair game for investigators, Joh said.
She pointed to the case of California v. Greenwood, in which the U.S. Supreme Court ruled in 1988 that police did not need a warrant to search a suspected drug dealer's trash because he should have had no expectation of privacy when he placed it on the curb. Trash, the judges wrote, is "readily accessible to animals, children, scavengers, snoops, and other members of the public."
But Joh argued comparing DNA and trash is a poor analogy.
"Obviously, we might want to discard that cigarette, but do we really mean to give up all kinds of privacy claims in the genetic material that might lie therein?" she asked.
As advances in technology make DNA analysis faster and cheaper, "I think of it really as a kind of frontier issue," she said.
Richards, meanwhile, pointed out that while abandoned DNA can confirm a suspect's identity, it also works to the benefit of someone who is innocent.
"DNA rules people in, but it also rules people out," he said.
That point was not lost on the husband of murder victim Barbara Lloyd, who was questioned for hours after he reported his wife's death from 16 stab wounds in their bedroom that March 1974 morning. Police ruled Galan Lloyd out as a suspect after a few days.
Chatt's arrest, he said, proved that was the right decision.
"If there were people out there who still thought I did it, this should do it," Lloyd, now 59, told The Buffalo News.
Barbara Lloyd was killed as her then-3-year-old son, Joseph, and 14-month-old daughter, Kimberly, slept. The now-grown children recently persuaded police to take another look at the killing, leading police to close in on Chatt.
"We were very fortunate that at that time there was a detective in the evidence collection unit who was able to secure evidence from the scene which was later used for comparison," Richards said. "Here we are 30 years later, able to open up a box and submit some of the items that we found and to have a DNA analysis done."
Joh suggests proceeding with caution.
"My hope is there will be much greater awareness of what this means, not just for these particular cases, but for everyone," she said. "Is DNA sampling going to be ordinary and uncontroversial for the general population, in which case abandoned DNA may not be so alarming, or does it raise a whole host of privacy questions?"
