Prosecutors: Suspect said he "lost it," killed NYC runner Karina Vetrano

NEW YORK -- Prosecutors say a man arrested in the death of a New York City runner told police he “lost it” and strangled the woman during a chance encounter.

Chanel Lewis pleaded not guilty Tuesday to first-degree murder and other charges in the Aug. 2 attack on Karina Vetrano, 30.

Vetrano’s father found her badly beaten body in a secluded marsh. Detectives following up on leads came across Lewis going back through old 911 calls, and found he had been the subject of a suspicious person report in the area where Vetrano was found slain three months before the attack, according to CBS New York. He reportedly voluntarily gave investigators a DNA sample that matched DNA found on Vetrano’s body.

Lewis was arrested in February. In court Tuesday, prosecutors said he gave a chilling confession to investigators after his arrest.

According to prosecutors, Lewis confessed he was upset with a man in his neighborhood and went for a walk in Queens’ Spring Creek Park. He said he saw Vetrano running and lost it, according to CBS New York.

He said he grabbed her and punched her in the face, according to prosecutors. He allegedly said he beat her to let the emotion out, becoming more mad each time he hit her. He said he broke her tooth, and Vetrano scratched him, the station reports.

Lewis said Vetrano fell into a pond of water and he strangled her until she stopped moving, according to prosecutors. He allegedly said he grabbed her by the wrists and pulled her into the weeds, and that’s when her pants fell down.

Prosecutors said he then asked detectives to tell her parents he was sorry for what he did, and that she didn’t deserve it.

Families of the victim and the suspect both attended the court hearing, reports CBS New York. Neither spoke to reporters.

The Legal Aid Society, which is representing Lewis, issued a statement saying it “looks forward to closely reviewing” prosecution documents. It has previously said it was concerned about how DNA was collected and about “the overall reliability” of evidence in the case.

Lewis’ mother has said he has mental health problems but would not hurt anybody.

Lewis is charged with first-degree murder, along with sexual abuse. He faces a possible prison sentence of 25 years to life if convicted.