ELMONT, N.Y. (CBSNewYork) — A suspect accused of fatally stabbing his ex-girlfriend at Belmont Park is set to face a judge on Monday.

Police say 53-year-old Jose Franco-Martinez is charged with second-degree murder.

Around 6:30 a.m. Sunday, police said he allegedly stabbed the 51-year-old unidentified woman as she was walking a horse after a training session.

Police said security officials knew something was wrong when they heard screams and found a horse running loose.

The woman had multiple stab wounds, police said. She was taken to the hospital by ambulance where she was pronounced dead.

“She was a really nice woman,” the victim’s friend, Humberto Garcia, said. “Came in here also, always get stuff. She was always trying to send money back to her kid in El Salvador.”

The suspect was arrested at the scene. Police said Franco-Martinez wasn’t a current employee at the track, but may have worked there in the past. It’s still unclear how he gained access to a back barn area.