Investigators were unable to confirm they were human remains until recently. Police returned to the home on Wednesday with a search warrant.
"We can't really say right now how many, whether it's one or two or three people. That would be pure speculation at this point," said Hemet Police Lt. Dean Evans.
Two 17-year-old boys, Adrian Rios and Jose Campos, and 17-year-old Felicia Sharpe were reported missing Nov. 17.
Sharpe was located Wednesday with her mother, and is now being interviewed by detectives.
Rios and Campos are still missing. Police do not believe they ran away and have called the case suspicious.
Authorities said Wednesday the remains are that of a single male victim.
Police are unsure if the remains are any of the missing teens, but Campos lives at the home where the remains were found.
Police said Sharpe is the girlfriend of Campos, and Rios was at Campos' home to watch a football game just two Sundays ago. Neighbors reported a bonfire in the backyard that night, then a day or two later, the teens were reported missing.
"It was a horrible, very bad smell," said neighbor Matthew Miller.
"I smelled something when I was laying in bed, and I was thinking the house was on fire, and I told my wife, 'What's that weird smell?" said one neighbor.
Rios' friends and family are worried about what may have happened to the teen.
"He was over at our house, and from there that was the last time we seen him. And the mom came looking for him, crying to us saying that he was missing," said Elizabeth Robles.
"He's just my friend. I've known him for a long time, just trying to find out what's going on," said Richard Robles.
Detectives said it could be weeks before the remains are identified.
"We have no idea who they are at this point," said Lt. Dean Evans of the Hemet Police Department.
Anyone with information is urged to call the Hemet Police Department at (951) 765-2400.