The body of an adult man was discovered next to Temple Emanu-El in East Meadow on Saturday afternoon.
Homicide detectives were at the scene. Authorities are trying to determine who the person is, and how he died.
A passerby told police they saw a man stumbling in the area shortly before the discovery was made.
There were no obvious signs of trauma to the body.
Police say the man does not appear to have any connection with the temple.