A notorious New Jersey serial killer was arraigned Wednesday in connection with the gruesome 1968 cold case murder of a young New Hyde Park mother at the Green Acres Mall in Valley Stream.
Richard Cottingham, now 75, is serving time in a New Jersey prison for other murders. His alleged victim, Diane Cusick, 23, was found dead inside her car, parked in the mall parking lot on Feb. 16, 1968. Nassau investigators say the cold case homicide was finally solved using new DNA testing technology, and Cottingham faces a potential 25 years-to-life sentence for Cusick’s murder.
“Thank you to everyone who worked on this case. I never thought I’d see this day; I had given up. But all these people got justice for me and for my mother,” said Cusick’s daughter, Darlene Altman, during a news conference following the arraignment on Wednesday.
She was surrounded by Nassau County District Attorney Anne Donnelly, Nassau County Police Commissioner Patrick Ryder, and Det. Steven Fitzpatrick, captain of the NCPD’s homicide squad. Donnelly pledged that her office would bring Cottingham to justice for Cusick’s murder. Chief Jared Rosenblatt, of the Homicide Bureau, is prosecuting the case, and Jeffrey Groder, Esq. is representing the defendant.
According to police, Cusick was a dance instructor at Wakefield Dance Studio, a dance school in Oceanside. She had just finished teaching a class at about 7 p.m. on Thursday, Feb. 15, 1968, and told her parents she was going to the Green Acres Mall to buy a pair of dancing shoes.
“She never returned home,” Donnelly said. “By 10:30 p.m., her father and mother became concerned. They drove to the shopping mall and looked at the parking field that she was known to use.”
Once Cusick’s parents spotted Cusick’s Plymouth Valiant car, they found her lying in the back seat. She had a bandage over her mouth, and her hands were bound. Officers were called to the scene, and she was officially pronounced dead at 1:40 a.m. on Feb. 16, 1968.
“As we know there have been amazing advances in forensic science,” Donnelly said. “In 1968, the NCPD worked very hard on this case. They followed countless leads [and] conducted many interviews with people in the area that evening and spoke to potential suspects. [Cusick] was separated from her husband who cooperated with the investigation and was not a suspect. Months became years and the case went cold.”
In mid-2021, NCPD learned that an incarcerated man could be responsible for murders on Long Island, Donnelly said. They then compiled a list of unsolved homicides, and the Nassau DA’s office requested that evidence in Cusick’s case be re-examined.
With new technology, a new DNA profile was created in Cusick’s case, uploaded to the national database, and came back with a match that led investigators to Cottingham, who was already listed in the database for previous crimes. Investigators also spoke with Cottingham and the first Nassau police officer who responded to the scene on the evening of Feb. 15, 1968 to piece the story together.
According to NCPD, Cusick and the alleged perpetrator did not know each other. Investigators say she was beaten before being strangled to death, and they believe that Cottingham posed as a security guard and accused customers of shoplifting in parking lots to lure in his victims, most of whom were young women.
Donnelly says that the D.A.’s office and law enforcement are now reviewing all unsolved homicide cases with young female victims from 1967 through 1980, when Cottingham was first caught.
Sign up for Long Island Press’ email newsletters here. Sign up for home delivery of Long Island Press here. Sign up for discounts by becoming a Long Island Press community partner here.
