Woman Pleads Guilty In Exchange For Cooperating Against Co-Defendant In Stony Brook Slaying: Attorney

RIVERSIDE, NY — An East Setauket woman pleaded guilty to first-degree manslaughter and has agreed to cooperate with the Suffolk County District Attorney’s office in prosecuting her codefendant in connection with fatally stabbing her ex-boyfriend in Stony Brook last November, her attorney said Wednesday.

Kacy Corso, 34, received the offer of a reduced charge in exchange for cooperating with prosecutors against Victor Panebianco, who is charged in the slaying of Christopher Millwater, 52, of Selden, on Nov. 10, according to Christopher Gioe of Hauppauge.

Corso remained in her car "throughout the altercation," and has "consistently expressed remorse," he said.

"She has agreed to cooperate with the prosecution and will face seven years of incarceration followed by five years of post-supervision," he added.

Corso was facing 25 years to life.

Patch has reached out to the DA's office.

Corso was charged in connection with the slaying of Millwater after he was found stabbed to death outside the Stony Brook Yacht Club.

Homicide Squad detectives charged Corso with second-degree murder for the stabbing death of Millwater, 52, of Selden, Suffolk police previously said.

Corso and her then-boyfriend, Panebianco went to the yacht club, knowing Millwater would be there, and she used her car to block him from leaving, and then slammed it into him, News 12 reported, citing court documents.

Millwater's sister previously told Patch that he had been fishing at the location where he was killed for around 30 years.

"He went there for peace, for tranquility," she said. "He did a lot of fishing there. I don't really know what else to say. He was just a wonderful person."