The decomposing bodies of five family members were found Sunday in a home in a gated San Clemente neighborhood, authorities said.
The bodies were believed to have been in the house overlooking the Pacific for up to two weeks, but it was not immediately known how the victims died, said Orange County Sheriff's Lt. Erin Giudice.
Relatives discovered the bodies just before 4 p.m. at the Sea Pointe Estates house. They were described as a woman in her 70s or 80s, a man and a woman in their 40s or 50s, and two women in their early 20s, who were twins.
They all lived in the house, Giudice said.
Giudice said neither homicide nor suicide could be ruled out, but she stressed that neighborhood residents should not be worried.
"We believe there's nothing for them to be fearful about," she said. "We're not actively looking for a suspect at this time."
Homicide investigators wore scuba-like breathing apparatus to enter the house because noxious fumes created by the decomposing bodies and the smell were so strong, Giudice said.
The family members were last seen two weeks ago, she said. Since then, the Orange County Sheriff's Department had been asked to check on the house. A sheriff's patrol car drove by May 14 and again Saturday, Giudice said. Deputies did not stop because nothing seemed amiss from a visual check of the residence, she said.
It was unclear whether relatives or neighbors requested the checks.
Giudice would not elaborate on where in the house the bodies were found, or if they had any wounds.
Residents of the hillside community said violent crime seldom occurs in the quiet neighborhood just east of Interstate 5.
James Adams, 55, and Tami Adams, 50, who have lived in the neighborhood for 21 years, said the family appeared to be close.
Tami Adams said the middle-aged woman who was found was a doctor.
"I saw the mom driving the kids to school all the time," James Adams said. "They seemed to be a close family, but they kind of kept to themselves."
Times staff writer Amanda Covarrubias contributed to this report.