An Indiana race horse found dead earlier this week was slain with a tool used to kill livestock, not a bullet as previously believed, authorities said Friday.
A necropsy performed on Lady May Z at Purdue University indicated the mare died from "blunt force trauma" that pathologists believe came from a "captive bolt gun."
Lady May Z was found dead in a pasture on Tuesday, one day before she was scheduled for a run at Balmoral Park in Crete.
The results of the necropsy leads investigators to believe the horse was killed deliberately.
"In order for this weapon to be used in this manner, the perpetrator would have had to hold the device up to the horse's forehead while the trigger was depressed," a statement from the Lake County (Indiana) Sheriff's Department said.
Authorities said they now believe whoever killed the mare had experience in the meat processing field.
Anyone with information is asked to contact the department at 800-750-2746.
The Humane Society is offering a $2,500 reward for information that leads to the arrest and conviction of Lady May Z's killer.