Ayer Police Lt. Brian Gill said that on Friday, March 29 at about 4:45 p.m., the Ayer Police were notified about an unresponsive person in a vehicle on Mill Street.
The Ayer Fire Department assisted at the scene and determined a middle aged male was deceased.
Ayer Police Detective Kellie Barhight was assigned to case.
The State Medical Examiner and the Massachusetts State Police are assisting with the investigation.
The man's identity is not yet being released.
Follow Mary Arata on twitter.com/maryearata.