Authorities have arrested the ex-roommate of a woman whose body was found walled up inside a Southern California apartment six years after she disappeared.

Forty-three-year-old Randolph Garbutt was arrested Thursday, a day after he was picked up on a traffic warrant. He remains jailed.

Authorities believe he bludgeoned 37-year-old Raven Campbell, who was reported missing in 2009.

Authorities acting on a tip found her remains walled up in a Lomita housing project apartment in July.

There's no word on a motive for the killing.

The Los Angeles County Sheriff's Department says Garbutt and two others were living with Campbell in the unit at the time she vanished. The other former roommates aren't suspected of involvement in her death.