ELMONT, New York (WABC) -- Authorities say a man is in custody after a woman was fatally stabbed on the grounds of the Belmont Park racetrack Sunday morning
At about 6:30 a.m., police received a 911 call of an injured female at the track in Elmont. New York Racing Association security reportedly became alarmed when they observed a loose horse.
After investigating the rear barn area, security discovered 51-year-old Maria Larin, of Elmont, with multiple stab wounds.
She was taken to an area hospital, where she was pronounced dead.
The circumstances that led to the stabbing are not yet known, but the victim's ex-boyfriend -- 53-year-old Jose Franco-Martinez -- has been arrested and charged with second-degree murder.
The victim is what is called a "hot walker," who cools down horses after a training session.
Belmont Park is home to the Belmont Stakes, the third and final race that makes up horseracing's Triple Crown.
(The Associated Press contributed to this report.)