The Edinburg Police Department is investigating the death of a K-9 officer with the Pharr-San Juan-Alamo Independent School District's police department. 

The death of officer Tillin occurred Wednesday during the first-ever RGV K-9 competition in Edinburg. He was found unresponsive inside a police unit parked at the arena. 

RELATED: Death of PSJA ISD K-9 officer under investigation

The report shows that officer Tillin's handler left him in the unit with the A/C turned on. When the handler came back, Tillin was not moving, and the A/C was blowing hot air, according to the report.

Police are investigating to see if the cause of death was a heat-related condition caused by the failed A/C system.