Cop went nonstop to crack case

Solving Karina Vetrano’s slaying started with a 911 call about a “suspicious person” in Howard Beach, Queens — and ended with a dogged cop from the neighborhood who was determined to track down her killer.

NYPD Lt. John Russo (inset) was singled out Sunday morning by Chief of Detectives Robert Boyce as a “key player” in identifying Chanel Lewis as the prime suspect.

Boyce said Lewis was first identified based on a “deepdive’’ follow-up into a 911 call from May 2016, about three months before Vetrano was fatally attacked.

Russo, a married dad of two girls under the age of 14, had heard about that 911 call at the time and drove by the area while off-duty the next day, according to sources.

He spotted Lewis, who sources said was either prowling in back yards or casing parked cars, in the area. Russo immediately called it in, ensuring that cops interviewed Lewis and recorded his personal information, sources said.

Last week, Russo reminded the detectives investigating Vetrano’s slaying about the incident, leading to a Thursday interview, during which Lewis “freely gave a swab” for DNA to the investigators, Boyce said.

The sample was rushed to the Medical Examiner’s Office, which at 3 p.m. Saturday tied Lewis to Vetrano’s slaying, according to sources.

Russo — whose eyes were rimmed with red at the news conference announcing Lewis’ arrest downplayed his role, when The Post caught up with him Sunday evening.

Asked if he felt like a hero, Russo insisted, “Not at all.”

“This is a job we do every day. On- and offduty, we’re police. Twenty-four hours a day, we’re the members of the Police Department.” Russo, 41, formerly ran the 13th Precinct detective squad in Manhattan’s Gramercy Park and now serves as Boyce’s liaison to all precinct-level detective squads.

Sources described him as an impeccable dresser and “respected” cop who is “very fluent” in NYPD procedure.

“John Russo is a great guy and a great cop ... He wanted to solve [the case] very badly because his family lives right there,” a source who knows him said. “He has a very keen investigative eye so it doesn’t surprise me that he’s the one who cracked this case.”

Meanwhile, another source said a tipster claiming to be related to Lewis had called Crime Stoppers “looking for money” but “didn’t want to testify.”

Cops “had been working, trying to convince this person to come forward and provide information,” the source added.