A group of media outlets are suing Dane County and the city of Madison for refusing to release the tape of a 911 call from a murdered UW-Madison student.

The Milwaukee Journal Sentinel, the Wisconsin State Journal and two television stations say the tape should be made available under the public records law.

The media outlets are also seeking copies of an internal investigation into how the call was handled, e-mails and memos about the call, and other documents.

Authorities say releasing the call would hamper the search for 21-year-old Brittany Zimmermann's killer.

Zimmermann, from Marshfield, was killed at her downtown Madison apartment in April.