LOWELL, Ind. (STMW) –– A racehorse found dead on Tuesday in northwest Indiana, the day before it was to race at Balmoral Park, was not killed with a gun as originally thought, but by a “captive bolt gun,” a necropsy has found.

Lake County Sheriff’s police found Lady May Z shot between the eyes about 7 p.m. Tuesday in a pasture near the corner of 245th Avenue and Colfax Street in Lowell, Ind., according to the sheriff’s office.

The 8-year-old standard bred trotting horse was scheduled to race Wednesday at Balmoral Park in south suburban Crete.

A necropsy performed by a forensic veterinary pathologist at Purdue University’s Animal Disease and Diagnostic Laboratory determined the death was the result of blunt force trauma to the brain from a captive bolt gun – a device used in processing plants to stun and kill livestock to be slaughtered, the sheriff’s office said.

Investigators initially thought the horse was shot with a bullet.

The suspect would have had to hold the device up to the horse’s forehead and depress the trigger, sheriff’s police said. They believe the suspect may have prior experience in the meat processing industry.

Sheriff’s Det. Michelle Dvorscak said the owners had other racehorses on the property, located in a secluded rural area, but no other horses were injured.

Anyone with information should call Dvorscak at (219) 755-3346, or call anonymously at (800) 750-2746.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)