Los Angeles County coroner's spokesman Craig Harvey identified the decomposed corpse as 53-year-old James Stein. Fingerprints confirmed his identity on Thursday.
Stein and his wife, Gabriela, have been missing since Dec. 9. She is still missing.
Authorities first got word there may be bodies buried in the backyard on Monday. The tip came from the ex-girlfriend of the prime suspect, Marcos Lomeli.
L.A. County Sheriff's investigators arrested Lomeli on Wednesday at a motel in Pico Rivera near Beverly and Rosemead boulevards. Lomeli also lived in the Lennox house.
Hours after Lomeli's arrest, the Lennox house caught fire. The blaze was under investigation by an arson unit.
Anyone with information about this case was urged to call Crime Stoppers at (800) 222-TIPS.
The Associated Press contributed to this report.
