MADISON, Wis. (AP) -- Dane County's chief executive says authorities mishandled a 911 call from the cell phone of a college student but she has confidence in her 911 chief.

County Executive Kathleen Falk says "the system didn't work like it should" when a dispatcher received the call from Brittany Zimmermann's phone on April 2.

The dispatcher eventually hung up on the caller, failed to call the number back and never sent a police officer to investigate. Zimmermann was found murdered in her apartment shortly after.

Madison Police Chief Noble Wray says the 911 call contained evidence that should have triggered a dispatch but county authorities have described it as a routine "hang-up" call.

Falk praised Joseph Norwick, director of the county's 911 center, as a skilled law enforcement official.