The coroner's office is still working to notify family and determine the cause of death. Police say there are no obvious signs of trauma, adding to the mystery.
[Ads /]
People who live in a four unit apartment complex waited for answers following the deaths. "They evacuated the building and we were all not supposed to go back in," said Marie Nadeau. "We received a call from a person who said they discovered one of the persons inside deceased.
Inside the unit, investigators discovered a second body and two dead cats.
"As their cause of death wasn't immediately apparent, the building was evacuated out of an abundance of caution," Barron White of the Berkeley police department told ABC7 News.
Police feared a carbon monoxide leak, but hazmat crews gave it the all clear.
[Ads /]
"All we know is that it's safe to go back in," said White. "It's not a gas leak."
Nadeau says a man and woman in their 30s lived in the unit, but she didn't know them well. "Just to say hi to in passing," she said. "They're very sweet."
Police received the call around 1 p.m. Monday afternoon. Detectives collected evidence as night fell.