Case of Jogger’s Murder Hinges, in Part, on Questions Over a Police Stop

On a block of nearly indistinguishable two-story homes in Howard Beach, Queens, Chanel Lewis and Lt. John Russo encountered each other for the first time on Memorial Day in 2016.

Lieutenant Russo, dressed in a tank top and shorts, was pulling up to his home. Mr. Lewis, wearing a track suit with the hood up, was walking slowly, stopping to look at houses, the lieutenant later testified. The man made Lieutenant Russo suspicious, he testified. So, with his two young daughters in the back seat, he trailed Mr. Lewis for more than an hour before losing sight of him on a commercial strip.

The next day, May 31, Lieutenant Russo spotted the 20-year-old again nearby. Mr. Lewis was pacing outside a parking lot. A 911 caller had reported seeing a man in a track suit going in and out of yards with a crowbar — and said he had seen the man the day before, too. After Lieutenant Russo drove over and found Mr. Lewis, he called the local precinct. Five officers pulled up and stopped and frisked Mr. Lewis.

That sequence of events is now among the points of contention in one of the highest-profile murder cases of late in New York City: the killing of Karina Vetrano, 30, who was sexually assaulted and strangled as she jogged in a Howard Beach park in August 2016. Mr. Lewis was arrested last year and charged with the murder. His approaching trial has generated fresh questions about what justifies stopping someone, and whether an illegal stop taints the information police officers get from it, even if all they get is a person’s name.

After a flurry of legal filings in recent weeks, a judge in Queens Supreme Court could rule on those questions as early as Tuesday.

The police released Mr. Lewis after his May 2016 stop once they determined he hadn’t committed a crime. He had no crowbar. No one in the area had reported a break-in. Prosecutors have not said if Mr. Lewis was even the man the 911 caller saw going into yards.

But Mr. Lewis’s name and birth date were memorialized in a police officer’s memo book. And that note led to his arrest eight months later when, in the middle of a stalled investigation into Ms. Vetrano’s killing, Lieutenant Russo had the memo book unearthed so detectives could investigate the man he remembered once arousing his suspicions.

Digging up Mr. Lewis’s name led them to notes from medical calls when Mr. Lewis, as a teenager, was in distress and told emergency responders “he wanted to hurt girls,” prosecutors said. Lieutenant Russo described Mr. Lewis to other police commanders as an “emotionally disturbed person.” Then detectives asked for a swab of Mr. Lewis’s DNA and, after they said it matched DNA from the murder scene, arrested him on Feb. 4, 2017, outside his home in East New York, Brooklyn. They later obtained a confession that Mr. Lewis’s lawyers have argued was coerced.

The police and prosecutors have portrayed the May 2016 stop as industrious police work by a lieutenant attuned to signs that something was amiss on his block.

To Mr. Lewis’s defense lawyers, the stop was redolent of the abuses of stop-and-frisk, an act of profiling that put Mr. Lewis under scrutiny because he was a black man walking in a mostly white neighborhood.

“Walking on a public street in Howard Beach, albeit very slowly and looking at homes, is not criminal, nor does this violate any sections of the penal law,” Mr. Lewis’s lawyers — Robert Moeller, Julia L. Burke and Jenny S. Cheung, all of the Legal Aid Society — wrote in a December filing. “Nor is it a crime to pace back and forth in front of a parking lot.”

With the 911 caller giving only a generic description of a black man in a black track suit and white top, the police did not have reasonable suspicion that Mr. Lewis had committed or was about to commit a crime, his lawyers argued. And after the police stopped him, officers drove Mr. Lewis to a McDonald’s in Far Rockaway, Queens, for reasons that remain unclear. The lawyers cited that trip as evidence that Mr. Lewis was detained for a prolonged period.

The lawyers argued that Mr. Lewis’s name and birth date were “the direct fruit” of an illegal stop and should be excluded. And because detectives were only able to ask Mr. Lewis for a DNA sample because they had his name from the stop, all the evidence that followed — the DNA swab and Mr. Lewis’s confession — should also be held out of trial, the lawyers argued.

“Before this unlawful encounter, Mr. Lewis’s pedigree information was not in the criminal justice system as he had no prior contacts whatsoever with law enforcement,” the lawyers said in their filing.

Prosecutors have pushed back, arguing that Lieutenant Russo thought Mr. Lewis was casing homes for a burglary on Memorial Day. And because Mr. Lewis “fit the basic description provided by a known witness” on the 911 call the next day, Lieutenant Russo also had reason to have Mr. Lewis stopped, they contended.

But even if the police illegally stopped Mr. Lewis, prosecutors argued, his name couldn’t be excluded on those grounds. In a Jan. 10 filing, they argued that Mr. Lewis’s name only led the police to information they already had, like his address and notes from his medical calls. And prosecutors cited previous cases that they said showed that letting a defendant’s name be suppressed would “undermine the administration of the criminal justice system.”

The case is a reminder that stop-and-frisk, shunned by Mayor Bill de Blasio and used less and less by the Police Department, remains a hotly contested piece of some criminal cases. Police failed to fill out a required formal stop-and-frisk report in Mr. Lewis’s case, an issue that a court-appointed monitor overseeing changes to stop-and-frisk policies has identified as a persistent problem.

The dispute over whether evidence the police gathered by stopping Mr. Lewis can be withheld from trial also highlights the erosion of the exclusionary rule, established by the Supreme Court, which says illegally obtained evidence should be kept from trials, said Stuart Green, a professor at Rutgers Law School.

He said a 2010 ruling by the New York Court of Appeals seems to have established that a name cannot be excluded from trial in New York, even if it is the result of an illegal stop. That ruling, he said, relied on somewhat “flimsy” reasoning and further limited what evidence could be excluded from trial.

“What they’re proposing here is an additional exception,” Mr. Green said. But, he said, “It’s handled a bit roughly here, and I think more needs to be said about why there is this exception.”

The rule about excluding evidence, he said, “has been so shot full of holes that there isn’t that much left of it in the end.”