LONG ISLAND, N.Y. (PIX11) — Rockville Centre, one of the toniest zip codes in Nassau County, may have been a dumping ground for notorious serial killer Richard Cottingham 50 years ago.

PIX11 News confirmed several cold cases in Rockville Centre — involving similar scenarios — are among more than a dozen under review by Nassau investigators. Law enforcement believes Cottingham was active between 1967 and 1980, which is when he was arrested in New Jersey while accosting one victim in a hotel room.

“There are 13 overall cases we had in that time frame,” a law enforcement source told PIX11 News. “We’re looking at which ones fit his M.O.”

PIX11 News visited Maine Avenue off Peninsula Boulevard in Rockville Centre Thursday, where we found a memorial to one of the murder victims whose case has not been solved.

The body of Mary Beth Heinz, a 21-year old nanny, was discovered in a brook there on May 10, 1972. She had been strangled, and police believe she was thrown off a small bridge on Maine Avenue.

Two months later, the body of a young woman from Queens, Laverne Moye, 23, was found in virtually the same spot. She, too, had been strangled. Investigators think her body was also thrown into the brook.

Less than a year later, the body of another Queens woman, 24-year-old Dorothy Anderson was found in a stream a half-mile away in Rockville Centre.

Just last week, the Nassau County District Attorney, Anne Donnelly, announced a review of cold cases from a 13-year period. She made the revelation after Cottingham was indicted for the 1968 murder of a young mom at the Green Acres Mall in Valley Stream.

The victim, Diane Cusick, was found strangled in the back seat of her car.

“We now have evidence he was here in Nassau County,” Donnelly said, as she noted DNA was preserved from the 1968 crime scene and matched with Cottingham’s genetic sample in a national database called CODIS.

“We have upwards of five other cases we’ve submitted DNA on,” said Detective Captain Stephen Fitzpatrick, commander of the Nassau County Police Homicide Squad.

Investigators in Nassau and five other jurisdictions have benefitted from the assistance of Jennifer Weiss, the daughter of a 1979 Cottingham victim who visits him in prison and encourages him to come clean on his crimes.

Weiss is working with criminal historian, Dr. Peter Vronsky, to connect the dots when Cottingham offers information on some of his murders.

“Persuading him to close these cases is not as easy as we may think,” Vronsky told PIX11 News.

Cottingham has made a dozen confessions since he went to prison more than four decades ago. But he pleaded not guilty in the Diane Cusick case last week.

There’s been speculation he didn’t want to confess in the Cusick murder because he wanted access to the “discovery” evidence offered by prosecutors.

Weiss has been photographed smiling with the serial killer, but she said there’s a reason for her affability with him.

“I always wanted him to feel comfortable enough for him to tell me the truth,” Weiss said. “My approach was definitely not conventional.”

Vronsky said Cottingham, a married dad who was living in Lodi, New Jersey, often visited a location near Jamaica Avenue and Springfield Boulevard in Queens Village. There are a number of cold case murders near the southern end of Springfield Boulevard where the female victims were strangled and sexually assaulted.

Sunrise Highway has also been a roadway of interest to investigators. Sunrise Highway starts on the eastern end of southern Queens and runs into Nassau and Suffolk counties.

Vronsky has said Cottingham claimed he killed between 85 and 100 women, and the historian is tracking at least 30 cold cases in New York and New Jersey.

“There’s a good 30, between 1963 — when I believe he killed his first victim at the age of 16 — and 1980, when he was arrested,” Vronsky said.