Four deaths at Sandy Lodge in Newquay between December 2024 and April 2025 are under review after James Desborough was convicted of murdering two fellow residents.
Devon and Cornwall Police said the dead were two men and two women, and a separate major-crime detective ordered extra forensic work, CCTV checks and witness statements.
Rachael Bentley said Desborough, 40, is not a suspect and police do not currently believe the deaths are linked to him, though inquiries remain ongoing.
Each death was initially attended by police and appeared to involve natural causes, but coronial investigations were paused after Desborough's arrest on the murder charges.
Desborough was also sentenced earlier this year for murdering his cellmate in Exeter Prison while on remand, making him a convicted triple killer.