ELMONT, N.Y. (CBSNewYork) — A man is facing murder charges after police say he stabbed his ex-girlfriend to death early Sunday at Belmont Racetrack on Long Island.

Police say security guards at the racetrack became alarmed when they noticed a horse running loose around 6 am. They proceeded to investigate the rear barn, where investigators say they discovered a 51-year-old woman with multiple stab wounds.

The victim was rushed to a nearby hospital where she was pronounced dead.

Jose Franco-Martinez, 53, was arrested at the scene and charged with second degree murder.

“The female was a hot walker,” Nassau County Homicide Detective Lieutenant Stephen Fitzpatrick said. “She cools the horse down, she walks them after they’re done with a training session.”

The victim was walking a horse at the time of the incident, according to Fitzpatrick. Her identification was being withheld pending family notification.

“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.”

Police say Franco-Martinez wasn’t a current employee at the track, but may have worked there in the past. He’s expected to face a judge on Monday.

Belmont Racetrack is home to the Belmont Stakes, the third and final leg of horse racing’s Triple Crown. Just last week, Justify won the 150th running of the Stakes to become the 13th Triple Crown champion in horse racing history.