Salt Lake City police still hope the body of Lori Hacking will be found somewhere in a municipal landfill.
Search dogs are scheduled to return to the site Wednesday night to renew efforts to locate Hacking's remains.
Police Chief Rick Dinse says detectives have found the weapon used in the homicide, and also know the motive. He hasn't elaborated on what that evidence might be.
Lori Hacking's husband, Mark Hacking, was arrested Monday and charged with one count of murder. He's currently under a jail suicide watch.
Dinse says an additional murder charge could be added later if Hacking's body is recovered and it's determined that she was pregnant. She had told friends she was five weeks pregnant.