DNA led to the arrest of Karina Vetrano’s suspected killer, six months after her battered body was found in a New York City park in a seemingly random killing. But a police source tells PEOPLE it was a neighborhood investigator’s hunch that really broke the case open earlier this year.

According to the source, who has knowledge of the investigation, N.Y.C. police Lt. John Russo played an instrumental role in capturing 20-year-old Chanel Lewis. He was arrested Saturday and is charged with Vetrano’s murder and sexual assault.

Russo, an observant cop with a sharp memory, lives in the same Queens neighborhood as Vetrano and her parents, the source explains. In May, he “remembered seeing some guy skulking around his neighborhood; was sort of looking into cars and over fences,” the source says. “That was three months before the murder.”

Russo called 911 about the suspicious figure, but the man was gone by the time officers arrived, the source says. The next morning, Russo spotted the man again. This time, police were able to question him and to file a record of their encounter.

What’s more, a 911 caller identified Lewis by name in a call in May, saying he looked as if he was breaking into a Howard Beach home with a crowbar, ABC News reports, citing police sources.

Lt. Russo alleges it was Lewis that he saw around the area in Queens, a source tells PEOPLE.

Two weeks ago — months later into the investigation and with the case still on his mind — Russo turned again to Lewis’ alleged activity last year, the police source says.

“He put two and two together,” the source says, and investigators began reviewing records to discover that Lewis had been issued several summonses near the scene of Vetrano’s death — one just days before the August slaying.

Russo “was spending a lot of time every single day trying to figure out what was missing,” one source reportedly said. “It occurred to him that was someone they should look at.”

Police tracked him to his mother’s house in Brooklyn last week. On Thursday, Lewis gave investigators a DNA sample, which was matched on Saturday to a sample recovered from Vetrano’s body, leading to his arrest.

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Lewis has yet to enter a plea to his charges and he remains held without bail. Lewis’ parents were unavailable for comment, as were his lawyers.

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Motive: A Hatred of Women?

Lewis is a professed misogynist who once threatened to attack several female students at his high school with a knife, police sources allege to PEOPLE.

Lewis allegedly told investigators he “hates ,” but detectives still have no idea where the suspected killer’s apparent contempt comes from, one source claims. (A second police source confirms this account.)

Police say Lewis admitted to Vetrano’s Aug. 2, 2016, killing, the first source claims. Authorities say that though he has denied he sexually assaulted Vetrano, Lewis told police he couldn’t stop himself from attacking the 30-year-old as she was jogging.

Her body was found by her father in a Queens park, about a dozen feet from a trail she used daily. She had been sexually assaulted and strangled to death. Investigators said she “put up a ferocious fight” before her death, capturing crucial DNA of her killer.

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“His parents are not being cooperative, and he has copped to it,” the police source explains of Lewis. One detective involved in the investigation characterized him as a “lady hater” — at odds with the reaction of Lewis’ father, who described his son as a “humble” man who had excelled in school.

Police confirm that Saturday was Lewis’ first arrest. But the source alleges that he generated at least one 911 call while he was a high school student.

Several years ago, according to the source, administrators at Lewis’ Rockaway Park high school contacted police after Lewis allegedly ranted about his disgust for the opposite sex and threatened to bring a knife to school to maim a number of female students.

Lewis was not arrested for that threat, but officers still documented the incident, according to the source, who claims that in recent years Lewis has made similar threats and sentiments — though without charges.

During his arraignment on Sunday, Lewis was reportedly confronted by Vetrano’s parents: Her mother called him a “demon.” But Lewis’ father, speaking to reporters after his son was arrested, said his son was peaceful.

“Chanel would never have gone to do what they say he has done,” his father said. “He’s never had a fight in his 20 years.”



