Quinton Simon, 20, has been presumed dead, police announced at Thursday's press conference.
Jeff Headley said:, Our investigation in eight days has led us to the heartbreaking conclusion that Quinton Simon is dead."
Police announced Wednesday that Quinton was dead and named his mother, Leilani Simon, as the prime suspect.
Leilani Simon has been considered a "primary suspect" in the death of Quinton Simon. Police "have not made any arrests or filed any charges" as of Thursday afternoon.
Headley said he does not know where Leilani Simon is now, but his department does not consider him a soaring risk.
Quinton was reported missing on October 5, but the investigation was turned into a criminal investigation on Monday following his disappearance.