A high-ranking firefighter in southern Arizona has been charged with murder in the cold case slayings of his ex-wife, her mother and a third woman.

Police say all three deaths stemmed from a child custody battle between Tucson Fire Department Capt. David Watson and his ex-wife, Linda Watson.

Linda Watson disappeared 15 years ago. Her mother, Marilyn Cox, and Cox's friend, Renee Farnsworth, were fatally shot in 2003.

The Pima County Sheriff's Department says Watson has been a suspect all along.

A fire department spokesman says Watson is on unpaid leave.

He was arrested Saturday and was being held on a $2 million bond.

It was not immediately clear whether he had a lawyer who could comment on the charges.