Phoenix man pleads not guilty in case of missing girlfriend

PHOENIX (AP) -- A Phoenix man arrested on suspicion of first-degree murder in connection with his missing girlfriend has pleaded not guilty.

Maricopa County Superior Court officials say 37-year-old Robert Interval entered his plea at his arraignment Tuesday.

His next scheduled court appearance is an Aug. 8 initial pretrial conference.

Phoenix police say detectives developed probable cause to arrest Interval on June 8 although the body of 34-year-old Christine Mustafa has yet to be located.

Mustafa was last seen on the afternoon of May 10 and failed to show up for her scheduled work shift the next morning.

Mustafa's family asked police to check on her welfare and they went to the home she shares with Interval.

Police say Interval told officers Mustafa left for work on foot.