The five teenage boys were sitting in a parked car in a gated community in Melbourne, Florida, when a police officer pulled up behind them.

Officer Justin Valutsky closed one of the rear doors, which had been ajar, and told them to stay in the car. He peered into the drivers’ side window of the white Hyundai SUV and asked what the teens were doing there. It was a Saturday night in March 2015 and they told Valutsky they were visiting a friend for a sleepover.

Valutsky told them there had been a string of car break-ins recently in the area. Then, after questioning them some more, he made an unexpected demand: He asked which one of them wanted to give him a DNA sample.

After a long pause, Adam, a slight 15-year-old with curly hair and braces, said, “Okay, I guess I’ll do it.” Valutsky showed Adam how to rub a long cotton swab around the inside of his cheek, then gave him a consent form to sign and took his thumbprint. He sealed Adam’s swab in an envelope. Then he let the boys go.

Telling the story later, Adam would say of the officer’s request, “I thought it meant we had to.”

Over the last decade, collecting DNA from people who are not charged with — or even suspected of — any particular crime has become an increasingly routine practice for police in smaller cities not only in Florida, but in Connecticut, Pennsylvania and North Carolina as well.

While the largest cities typically operate public labs and feed DNA samples into the FBI’s national database, cities like Melbourne have assembled databases of their own, often in partnership with private labs that offer such fast, cheap testing that police can afford to amass DNA even to investigate minor crimes, from burglary to vandalism.

And to compile samples for comparison, some jurisdictions also have quietly begun asking people to turn over DNA voluntarily during traffic stops, or even during what amount to chance encounters with police. In Melbourne, riding a bike at night without two functioning lights can lead to DNA swab — even if the rider is a minor.

“In Florida law, basically, if we can ask consent, and if they give it, we can obtain it,” said Cmdr. Heath Sanders, the head of investigations at the Melbourne Police Department. “We’re not going to be walking down the street and asking a five-year-old to stick out his tongue. That’s just not reasonable. But’s let’s say a kid’s 15, 16 years old, we can ask for consent without the parents.”

Members of the Baltimore Police Department walk near the intersection of North and Pennsylvania Avenues, the site of unrest following the funeral of Freddie Gray, in Baltimore, Thursday, June 23, 2016. Associated Press/Patrick Semansky

In Bensalem Township, Pennsylvania, those stopped for DUI or on the street for acting suspiciously may be asked for DNA. Director of Public Safety Frederick Harran credits the burgeoning DNA database Bensalem now shares with Bucks County’s 38 other police departments with cutting burglaries in the township by 42 percent in the first four years of the program. Plus, Bensalem pays for the testing — which is conducted by a leading private lab, Bode Cellmark Forensics — with drug forfeiture money, making it essentially free, Harran added.

“This has probably been the greatest innovation in local law enforcement since the bulletproof vest,” Harran said. “It stops crime in its tracks…. So why everyone’s not doing it, I don’t know.”

While Harran tells his officers to be careful not to push people to consent, civil rights advocates see a minefield in cases that morph from stop-and-frisk to stop-and-spit.

There are clear precedents for obtaining DNA from people who have been convicted of crimes and from those under arrest. Under the Fourth Amendment, law enforcement must have a reasonable suspicion that a person is involved in a crime before requiring a search or seizure.

But the notion of collecting DNA consensually is still so new that the ground rules remain uncertain. Who can give such consent and what must they be told about what they’re consenting to? Who decides how long to keep these samples and what can be done with them? Maryland’s Supreme Court is the highest to rule on such a case, saying in 2015 that law enforcement could use DNA voluntarily provided to police investigating one crime to solve another, but that case didn’t take on DNA collected outside of an investigation, in chance street or traffic stops.

More challenges seem inevitable, said Jason Kreag, a University of Arizona law professor who’s written about local law enforcement’s expanding use of DNA. Police interviews that lead to DNA collection — particularly involving juveniles—have the potential to create “a coercive environment,” he said. “The laws and the legislatures just haven’t caught up with this type of policing yet.”

Harran echoed that. “There’s no laws, there’s nothing,” he said. “We’re in uncharted territory. There’s nothing governing what we’re doing.” He wants for private database programs to establish their own best practices.

Private DNA databases have multiplied as testing technology has become more sophisticated and sensitive, enabling labs to generate profiles from so-called “touch” or “trace” DNA consisting of as little as a few skin cells. Automated “Rapid DNA” machines allow police to analyze DNA right at the station in a mere 90 minutes. Some states allow “familial searching” of databases, which can identify people with samples from family members. New software can even create composite mugshots of suspects using DNA to guess at skin and eye color.

Strict rules govern which DNA samples are added to the FBI’s national database, but they don’t apply to the police departments’ private databases, which are subject to no state or federal regulation or oversight. Adam’s DNA, for example, was headed for a database managed for Melbourne by Bode Cellmark Forensics, a LabCorp subsidiary, which has marketed its services to dozens of small cities and towns. The lower standards for DNA profiles included in private databases could lead to meaningless or coincidental matches, said Michael Garvey, who heads the Philadelphia Police Department’s office of forensic science, a public lab.

“No one knows what the rules are about what they’re going to upload into these private DNA databases or not,” Garvey said. “Mixtures, partials — what’s their criteria? It varies.”

When Adam’s father found out the police had taken his son’s DNA, he immediately contacted the Melbourne Police Department to ask what the department intended to do with the sample and on what legal basis it had been taken. As a doctor, he understood what had happened could have far-reaching implications.

“My concern, being in the medical field, is that it’s not just Adam’s DNA,” he said. (ProPublica is withholding his name to protect the privacy of his son.) “It’s my DNA, it’s my wife’s DNA, and our parents. Not to sound bad, but you just get nervous. There’s some collateral damage there.”

Sanders explained that Adam had given his consent, making the sample usable under department policy, though it had not yet been sent to the lab for testing. He said that as long as Adam didn’t get into trouble, the family had nothing to fear.

Unsatisfied and determined to get the sample destroyed, Adam’s dad took the only other step he could think of — he called a lawyer. It was attorney Jason Hicks’ first encounter with a stop-and-spit case. He quickly realized he and his clients were on the edge of a legal frontier.

“First, I was just shocked that it had happened,” he said. “Then I was frustrated by the lack of a vehicle to challenge it.”

Traditionally, certified local, state and federal forensic labs have tested DNA collected for law enforcement purposes, funneling these profiles into the FBI-run Combined DNA Index System, or CODIS.

The FBI’s standards for profiles uploaded to CODIS are rigorous. CODIS will only accept “partial” profiles under certain circumstances, and all samples must be tested by FBI-approved labs. The national database includes DNA from convicted offenders and arrestees in some states, but not from people merely suspected of crimes. State law dictates when databases linked to CODIS must toss out DNA profiles.

Private databases do not have any such constraints. FBI agent Ann Todd said that the DNA profiles stored in private databases would not be eligible for inclusion in the national database because “those profiles do not meet the strict eligibility, quality, and privacy standards set forth in the federal law.”

Smaller jurisdictions used to rely on larger ones for DNA testing, but many public labs have become backlogged as demand for their services has risen. In 2012, New York became the first state to require DNA collection from those convicted of any crime, not just violent ones, and at least 29 states now authorize collection from anyone arrested for certain crimes. Many states have also passed laws requiring DNA evidence from rape cases to be tested within a certain amount of time, increasing pressure on public labs.

Private operators have stepped in to meet the appetite for testing in cities and towns that can’t afford their own labs and have few violent crimes that would rise to the top of a public lab’s priority list. Bode Cellmark Forensics charges about $100 to $150 a swab — little enough for cops to swab everything from the steering wheel of a stolen car to the nozzle of a spray-paint can used for vandalism — and boasts a 30-day turnaround time for results.

Palm Bay, Florida, launched the nation’s first private DNA database program about a decade ago, working in partnership with DNA:SI, a private lab in North Carolina founded by Amway executive Bill Britt. The lab offered its services for free for the first year in exchange for Palm Bay’s spreading the gospel to other police departments. The program’s aim was for high-volume collection and testing to help solve the area’s high-volume crimes, which were mainly property crimes.

Sure enough, the first “match” solved a string of break-ins at the gated community where the city’s then police chief, William Berger, resided. The burglar even hit Berger’s house, slicing through a screen and stealing a couple of floats from his swimming pool. Berger brought in a canine team, which tracked the floats to the woods, then had the floats and the screen door latch swabbed for DNA. Five days later, a young man was caught attempting to shoplift at Wal-Mart. The Palm Bay police officer called to the scene didn’t make an arrest (the store declined to press charges), but the shoplifter consented to a voluntary DNA test. Turned out the shoplifter was also Berger’s burglar.

Encouraged by that success, Palm Bay police collected over 800 reference swabs from crime suspects in the first 10 months of the program, plus over 1,600 crime-scene items and evidence swabs. Five years later, the database contained profiles from about 3,500 people. “We were way ahead of the game,” said Berger.

In this April 19, 2007 file photo, a lab officer cuts a DNA fragment under UV light from an agarose gel for DNA sequencing. Wong Maye-E/Associated Press

Since its database remained siloed, apart from interconnected local, state and federal collections of DNA, the department understood that collecting a high volume of samples was critical.

To start, officers swabbed every single crime scene, no matter how minor the crime, said John Blackledge, then Berger’s deputy. Blackledge and his colleagues would decide which crime scene and suspect swabs to send to the lab, and in what order.

“It had to be that there was reasonable suspicion that this person was involved in criminal activity that fit within the interesting cases that we were working,” he said. “On top of that, the officer had to write a clear report that convinced me that this was either a free and voluntary swab, or that we had to get a search warrant.”

Since then, the department’s DNA collection seems to have become more aggressive. Sgt. Michael Pusatere, who now heads the department’s Crime Scene Unit, says officers work to solicit DNA from “repeat offenders” and people with whom the department comes into contact frequently, as well as people hanging out in high-crime areas late at night.

“We try to get as many people as we can into the database,” Pusatere said. “A database of four or five people isn’t really usable within a city of 106,000 people.”

Blackledge said building a private database also allowed the city to collect more DNA from juveniles. When Palm Bay’s program was starting, the Florida Department of Law Enforcement’s DNA database, which feeds into the FBI’s national one, contained profiles from over 297,000 adults, but only 35,000 juveniles. “They’re very reluctant to take juveniles,” Blackledge said. “That’s half of my freakin’ violators!”

In the years since Palm Bay started its program, neighboring police departments in Melbourne, West Melbourne and several small beach communities followed their lead, signing contracts with Bode Cellmark Forensics after DNA:SI went out of business. West Melbourne said it ended its collection program in May because it wasn’t delivering enough hits, but every four to six weeks, Palm Bay and Melbourne submit anywhere from 25 to 100 swabs apiece. They estimated that, collectively, they had amassed 7,000 or 8,000 reference and evidence samples spanning the region.

Many of the reference swabs are so-called “elimination” or “victim” samples, swabs taken from crime victims to eliminate them from the DNA mix during analysis. Others are from so-called “field interviews” — people who volunteer them during traffic stops, street stops and other consensual encounters with police.

Most big-city police departments say they do not solicit voluntary DNA samples under these circumstances — only from victims, or, occasionally, suspects associated with specific crimes. When asked about DNA collection during traffic or street stops, Rana DellaRocco, director of the Forensic Laboratory Section of the Baltimore Police Department, laughed and said, “God, I think if they even tried to suggest that, I think that our ACLU might actually have the top of their heads explode.”

New York City Police officers (NYPD) detain a demonstrator during a protest against U.S. Republican presidential candidate Donald Trump, outside the Trump Tower building in midtown Manhattan in New York March 19, 2016. REUTERS/Brendan McDermid

According to a document obtained through a public information request, the Melbourne Police Department collected 307 cheek swabs in 2015, most of which were elimination samples. Fifteen were taken from suspects in connection with a particular crime; nine more were taken when suspects were arrested; and 38 were taken during field interviews unconnected to any particular crime.

Nationwide, local law enforcement agencies that have started DNA collection programs have taken a variety of approaches deciding whose DNA they will seek and under what circumstances.

Only Palm Bay, Melbourne, and West Melbourne said they have asked juveniles to volunteer their DNA without getting their parents’ permission.

Since 2007, the District Attorney’s office in Orange County, California, has offered certain non-violent offenders the chance to have their charges dismissed in exchange for contributing cheek swabs to a special separate DNA database — a “spit and acquit” program, as the local media nicknamed it. As of mid-August, according to the DA’s office, over 145,000 people had voluntarily donated their DNA to this database.

Unlike their Florida counterparts, police in Greensboro, North Carolina — one of 16 departments that make up the North Carolina DNA Consortium — don’t gather samples through street or traffic stops. Instead, they started their program by approaching people who were repeat offenders or in ankle monitor programs, asking them to hand over DNA. Now they get samples from suspects connected to, or arrested for, particular crimes.

Police in Branford, Connecticut, draw a different line in collecting DNA. They’re instructed to request DNA from people they merely observe acting inexplicably or strangely. “Say we’re having a lot of problems with car break-ins, and we see you walking in a neighborhood where there are normally car break-ins, and you’re out at two o’clock in the morning,” said Capt. Geoffrey Morgan of the Branford Police Department. When people don’t offer persuasive answers for why they’re there, officers may get suspicious and ask for a swab. “And you know how many people say, ‘No, I don’t mind’?” Morgan added. “A lot.”

Morgan said his officers always get consent in writing, and often also record the process with their body cameras. Police in Melbourne, Bensalem, and Greensboro say they insist on getting consent, too, but other departments acknowledge their databases include samples gathered without it. West Melbourne police say they’ve collected “abandoned DNA” from chewing gum or cigarette butts left by people who refused to sign consent forms. Fairfax County, Virginia, police try to record consent in writing, but it’s not always possible.

“In some circumstances in the field, Patrol Officers do not always have forms readily available,” public information officer Don Gotthardt said in an email.

Police departments with private DNA databases also vary in how they respond to requests to throw out DNA donated voluntarily.

The North Carolina DNA Consortium will expunge a sample if a person submits a letter asking them to, said Stephen Williams, the Greensboro Police Department’s director of forensic services. But Branford, Connecticut, wouldn’t honor such requests.

“They can ask, but we don’t necessarily have to,” Morgan said. “I mean, if they gave it to us consensually, then they gave it to us consensually.”

Adam hadn’t been charged with a crime, so there was no criminal court that his attorney, Jason Hicks, could approach to have the evidence thrown out. Hicks also couldn’t find any case law emanating from litigation over similar cases.

Hicks zeroed in instead on the consent form Adam had signed and, in particular, whether he had genuinely understood he could refuse the police officer’s request for DNA.

Since Officer Valutsky had told the boys to stay in the car, Hicks reasoned it had been pretty clear to them that they wouldn’t be allowed to leave unless one of them handed over DNA. That sounded more like an illegal detention than a consensual conversation, the attorney charged, one that was not justified by the officer’s reference to previous “suspicious activity” in the neighborhood.

Damian Dovarganes/AP Images

“Law enforcement has to have a reasonable suspicion that those kids are specifically committing a crime,” Hicks said. “Not just that some clowns in the neighborhood had committed some crimes in the past — that doesn’t let them create a police state into infinity.”

When Hicks wrote to Cmdr. Sanders and made this argument, Sanders initially struck a conciliatory note, agreeing to toss the sample even though he disagreed that the police had acquired it illegally.

“As long as Adam is not a frequently seen name in our police reports I would not have a use for his sample,” Sanders wrote to Hicks in a July 16, 2015 email. “Since his encounter with the officers Adam’s name has not resurfaced, nor is there another entry for Adam in our computer system. Therefore, in order to end this situation I will have the items collected in this case removed from our files and destroyed.”

Subsequently, however, Sanders told Hicks that the sample couldn’t be destroyed until the City of Melbourne arranged a new contract with a company that handled the disposal of forensic evidence. He also expressed concern that expunging Adam’s DNA would create a precedent that could jeopardize the legitimacy of the whole DNA collection program. Hicks didn’t care about precedent, just his client.

The dispute meandered on for months, with Hicks checking in every so often with Sanders to ask about Adam’s DNA sample and being told it was still sitting in a pile marked “to be destroyed.”

Finally, on August 23—a year and a half after Adam handed over his cheek swab—Sanders sent word the sample would be destroyed the very next day.

Adam’s family was relieved the wrangling was over, but Hicks remains concerned that police continue to pursue voluntary DNA collection, with few constraints on how they gather genetic material and from whom. “If this is okay, what’s to stop police from walking up to children on a playground or a basketball court and sticking Q-tips in their mouths?” Hicks said. “As a parent, I get concerned about the erosion of the Fourth Amendment over time.”

Adam’s dad still can’t believe his son needs parental consent to go on school field trips or to learn to drive a car, but not to give up his DNA to the police under Florida law.

“For me, the crux of it is, can they ask for an underage kid to consent to something like that without a parent?” he asked. “According to the police department, that seems to be their policy. But to the general public, I think that would be news to them.”