Police said 49-year-old Michael Bresnak, who was already in jail for an unrelated case, was arrested Wednesday on suspicion of killing Jeffrey Korber.
Korber had been missing for more than two years before officers found his body in his girlfriend's storage unit in June.
Police said then that they believed Bresnak killed Korber at his mother's Ventura home and that she helped him store the body.
It wasn't immediately known what ultimately led investigators to arrest Bresnak.
The Ventura County Star reports ( http://bit.ly/19MX41m) a judge has denied the newspaper's request to unseal search warrant documents related to the case, saying it could jeopardize the ongoing probe.
Information from: Ventura County Star, http://venturacountystar.com