Christine Mustafa's boyfriend arrested, accused of first degree murder

Phoenix Police announced Thursday afternoon that the boyfriend of missing 34-year-old Christine Mustafa had been arrested, and booked on a count of First Degree Murder.

According to the statement, Robert John Interval Jr., 37, was arrested by detectives Thursday. Mustafa, 34, was last seen at approximately 3:00 p.m. on May 10, and was not heard from since the early hours of May 11.

On Thursday night, Eric Neathery and Diane Strand spoke to the media, on behalf of Mustafa's family.

"It's very, very difficult for them," said Neathery. "They are relieved but they know there's a lot yet to come."

Phoenix Police Sergeant Jonathan Howard said they had been building a case, since Mustafa was reported missing on May 11.

"We're talking about physical evidence," said Sgt. Howard. "We're talking about technological evidence, witness statements, and the case continued to build over the last 30 days."

Police said on Thursday that information on the case remains limited, as Mustafa's body has yet to be found.

"At this stage, the best that we can hope for is finding her remains and bringing her home to give her a decent burial," said Neathery. "It's unfortunate to have to say that."