Cottingham's confirmed killings resulted in nine convictions and a further eight confessions under non-prosecution agreements, leading to him serving multiple life sentences in New Jersey prisons.

[5] At Blue Cross, Cottingham worked in an office with Rodney Alcala, a fugitive child molester and serial killer who lived in New York under the alias "John Berger."

On August 21, 1972, he was charged and convicted of shoplifting at a Stern's department store in Paramus, New Jersey, and was sentenced to pay a $50 fine or ten days in jail.

[5] In the early morning hours of May 22, 1980, Cottingham picked up 18-year-old prostitute Leslie Ann O'Dell, who was soliciting on the corner of Lexington Avenue and 25th Street in Manhattan.

When arrested, he had handcuffs, a leather gag, two slave collars, a switchblade knife, replica pistols, and a stockpile of prescription pills.

In April 1978, after his wife had initiated divorce proceedings, he kept a locked room in a basement apartment of the house in which they lived in Lodi, New Jersey.

[8] During his 1981 trial, three additional surviving abduction-rape victims testified along with O'Dell against Cottingham in court, claiming that they had also been sexually abused and tortured by him.

Cottingham often sought sex workers in their late-teens to mid-twenties and is believed to have killed people in Florida, Connecticut, New York, Pennsylvania, New Jersey, and Baltimore.

He would approach his victims in bars, drug them, take them to a remote location and would bind, gag, torture, and stab them before killing them by strangulation or asphyxiation.

[2] In 2000, a detective in the Bergen County Prosecutor's Office (BCPO), Robert Anzilotti, was tasked with reviewing a series of cold cases from the 1960s and 1970s.

In December 2019, forensic historian and author Peter Vronsky, on the eve of publishing the revelation in his second edition of Serial Killers: The Method and Madness of Monsters, publicized the confessions with the BCPO's co-operation.

[5] The confession was extracted by Anzilotti weeks before his retirement and was facilitated by Vronsky and by Jennifer Weiss, the daughter of Deedeh Goodarzi, one of Cottingham's later victims.

[20] On August 26, 2022, with a non-prosecution agreement, officials in Rockland County, New York, corroborated and accepted Cottingham's confession to the 1970 murder of 26-year-old Lorraine McGraw.

[22][23][24] He pleaded guilty in a court appearance on December 5, and also officially admitted killing four other women during 1972 and 1973 in Long Island, New York: Mary Beth Heinz,[25] Laverne Moye,[22] Sheila Heiman,[26] and Maria Emerita Rosado Nieves.

Two focused entirely on him: Rod Leith's The Prostitute Murders: The People vs. Richard Cottingham (Lyle Stuart Inc., 1983) and Crime Scene: The Times Square Killer (Netflix, 2021).