Deputies had gone to check on the couple when one of them didn't show up for work. When they arrived at the home in Winchester, located west of Hemet, they found the front door open.
The cause of death has not yet been determined.
Neighbors said the couple purchased the house four to five months ago and believed the male victim was a Marine. Neighbors also said the female victim was often wearing hospital staff attire and may have been a nurse.
The couple's mysterious death has shocked the neighborhood.
"It's very scary. I've told my kids until further notice, until we find out a little more about the situation, we're going to and from school, that we're not playing at the park, we're not doing anything other than what we have to do until we find out more 'cause we don't know at this point," said neighbor Rachel Herring. "No one's telling us anything. The police aren't telling us anything. We don't' know whether our neighborhood is safe or not."