Authorities said the homeowners woke up and noticed a dog in their backyard in the 700 block of Camino Grove Avenue at about 8 a.m. They went out to investigate and discovered the man's body in the pool.
"Residents discovered a dog in their yard that didn't belong here and further inspection of their backyard they found a deceased male in their pool," said Arcadia Police Sgt. Steve Fallavollita
Authorities have identified the body as 35-year-old Greg Chen. They say the residents who found him did not know him. Police say he was from the Arcadia area but did not live in the neighborhood where his body was found.
Police do not believe foul play was involved. They believe the victim may had been at the bottom of the pool for hours before his body was discovered.
The pool is gated so it remains a mystery how the victim ended up in the water.
Police say the coroner will determine an exact cause of death. The dog is believed to have belonged to the victim. The Pasadena Humane Society said the man's family picked up the dog.
Anyone with information is urged to contact the Arcadia Police Department at (626) 574-5150, and refer to case #13-3713. You can also call L.A. Regional Crime Stoppers at (800) 222-8477.