MADISON, Wis. -- Four entire pages are missing from a newly released 40-page report documenting the handling of a 911 emergency call from the slain University of Wisconsin-Madison student Brittany Zimmermann's cell phone the day that she died.

READ: Dane County 911 Center Report (PDF Format) | TALKBACK: What Do You Think? |

Other pages of the report, which was commissioned by Dane County, are heavily redacted, WISC-TV reported.

Dane County officials said that their corporation counsel, Madison Police Department and the district attorney's office all took part in redacting the document. The reasons they cited for excluding some information from the public version of the report were to protect the police investigation and subsequent prosecution as well as safeguarding information that could be related to a personnel disciplinary proceeding.

There are few if any new revelations from the information that was released Thursday night after a special joint meeting of the county's Personnel and Finance and Public Protection and Judiciary committees on the 911 center.

During that meeting, 911 center director Joe Norwick was questioned by county committee members about what county officials and police said was a mishandled 911 call from Zimmermann's phone on April 2. They said that the operator answered the call, heard no response to her questions asking if there was an emergency, hung up on the call and then never called the number back. Officers were never sent to investigate.

On Wednesday, union officials representing the dispatcher who requested a transfer unrelated to the incident, disputed those accusations. The dispatcher said she made the right decisions and followed 911 protocols when she took the call, according to Laurie Lane, the chief steward of the dispatcher's union.

Lane said that she listened to a recording of the 911 call and she heard nothing on the call except some background noise, something like the rustling of papers. She said that there was no reason she could discern to immediately dispatch police.

Madison Police Chief Noble Wray last week unequivocally contradicted that, saying police should have been sent.

The report doesn't release the time of the call, which could shed light on whether police could have helped the 21-year-old UW junior or locate her attacker. Most of the report is comprised of a copy of Dane County 911 policies and procedures and 10 pages of non-descriptive 911 call activity that reveals little. The document also includes Internet and e-mail activity by the dispatcher in question the day that she received the call.

The report cites the operator for failing to call back the Zimmermann phone and for failing to immediately alert police to the call that followed that one -- a landline hang-up call from the Town of Middleton. After that hang-up, the operator called that landline number back and two men told her the call was a mistake. Procedure says any landline hang-up should automatically result in a police dispatch to the location.

The report criticizes the dispatcher for not calling the Zimmermann phone back.

"The chain of events surrounding the call suggest that (the dispatcher) having heard no indication of trouble on the call, chose to move on to another waiting call with the intention of calling back the first when (she) had the opportunity. (Her) failure to call back appears to be due to an unintentional oversight likely due to (her) moving on to handle subsequent calls," it says.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.