Kacy Corso pleads not guilty to charge she killed ex-boyfriend at Stony Brook Yacht Club

A Setauket woman pleaded not guilty to a second-degree murder indictment Wednesday in the fatal stabbing last month of her ex-boyfriend at the Stony Brook Yacht Club.

Kacy Corso, 33, appeared in a Riverhead courtroom Wednesday following a grand jury's indictment on charges of murder and hindering prosecution. Authorities said she confronted her ex-boyfriend, Christopher Millwater, 52, of Selden, Nov. 10 at the yacht club, rammed his car, and her new boyfriend, Victor Panebianco chased him down and stabbed him.

Suffolk County Judge Timothy P. Mazzei ordered Corso remanded in jail without bail.

Authorities said Panebianco, 32, was arrested in North Carolina and was expected to be extradited to be arraigned on the indictment Thursday, following a criminal complaint accusing him of stabbing Millwater several times.

Corso and Panebianco said in Facebook posts that she had rejected Millwater's advances and he had been harassing her.

Prosecutors said in court Wednesday that Corso was captured on police body cameras saying, "She was afraid of what she would do with him," Suffolk Assistant District Attorney Sheetal Shetty told the court.

"The defendant was in a long-term relationship with Christopher Millwater, and that relationship ended badly," Shetty said.

There were no allegations of physical abuse between Millwater and Corso, Shetty said.

Prosecutors said Corso and Panebianco, went to Millwater's sister's house looking for him.

Shetty said when Corso was then asked by police if she was afraid of Millwater, "She said, no, she was afraid of what she would do with him, if he didn't stop contacting her."

Corso also told police, "If they weren't doing anything for her, she would handle it herself," according to Shetty. "She followed through with that promise."

Prosecutors said Corso and Panebianco came to Long Island from out of state and were tracked as being in Stony Brook near the time of the killing, Shetty said.

Video surveillance showed the couple going to the yacht club, and Shetty said Corso used her car to block Millwater's vehicle in the parking lot while Panebianco ran toward him with a knife.

Prosecutors said Millwater tried to drive away when Corso drove "full force" into his car, sending it spinning through the parking lot.

Millwater began running from Panebianco, who prosecutors said was chasing him with a knife, while Millwater was yelling for help.

Prosecutors said Panebianco cornered Millwater and straddled him from above. Corso began telling Panebianco, "He shouldn't be fooled by the pleas for help," before he stabbed Millwater multiple times, Shetty said.

Prosecutors said the couple fled the state the same day, with license plate readers tracking them across four states to North Carolina, Shetty said.

Police recovered the vehicle, clothing and a knife, Shetty said.

If convicted, Corso faces 25 years to life in prison on the murder charge and up to 7 years on the charge of hindering prosecution, Shetty said.

Corso's defense attorney, Christopher Gioe, said Corso did not kill Millwater. He said she had returned to Suffolk County court to settle a landlord case prior to her arrest.

"My client didn't stab anybody. My client was not involved in the murder," Gioe said. "They have to prove she had the requisite mental intent when she was not the person doing the stabbing."

Corso's parents and Millwater's family sat in the courtroom during the arraignment but did not comment after the hearing.

Corso is scheduled to return to court Jan. 14 for the next hearing in the case.

By John Asbury

john.asbury@newsday.comJohnAsbury

John Asbury is a breaking news and general assignment reporter. He has been with Newsday since 2014 and previously worked at The Press-Enterprise in Riverside, California.