MADISON, Wis. -- Search warrant documents mistakenly left unsealed by the Dane County District Attorney's Office and Madison detectives, and obtained by WISC-TV, indicate that a 911 call from a University of Wisconsin-Madison student's cell phone the day she died included sounds of a woman's screams and noises of a struggle.

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The warrants also shed new light on the time of Brittany Zimmermann's slaying, how the intruder got in and the brutality of the slaying. The documents revealed that Zimmermann called 911 for help, apparently as she was being attacked. But the reason why help was never sent remains unclear.

The search warrants include police statements that describe the 911 call placed by Zimmermann on April 2, about 50 minutes before the 21-year-old student from Marshfield was found dead on the apartment floor by fiancé Jordan Gonnering.

A warrant in April said Zimmermann dialed 911 at 12:20 p.m. for help.

But Dane County officials said the dispatcher lost contact, didn't call Zimmermann back and didn't send police to investigate. County officials have said the 911 Center dispatcher mishandled the call.

In May, Madison Police Chief Noble Wray said that the dispatcher should have sent police but didn't.

"There is evidence contained in the call which should have resulted in a Madison officer being dispatched," Wray said in May.

Now that assertion by Wray is apparently being supported by the six newly released search warrant documents.

The warrant said, "the disconnect call started with the sound of a woman screaming. The line remains active and open, picking up the background sounds of a struggle for a short period of time."

But exactly what the dispatcher heard is unclear, WISC-TV reported.

Kathy Krusiec, interim director at the county 911 Center, reiterated in a statement Tuesday that "an investigation done in May by the 911 Center found no evidence the dispatcher heard anything that indicated an emergency was occurring."

But why the dispatcher didn't hear signs of an emergency remains unknown. Dane County officials said the dispatcher was not distracted and that the equipment was functioning properly.

In a statement, Krusiec said "disciplinary proceedings in association with the dispatcher involved with this call will be complete this month" and noted that the dispatcher, a 20-year veteran of the Public Safety Communications Center, hasn't been employed at the 911 Center since April 13.

The documents said a stranger likely killed Zimmermann after forcing entry through a security locked front door and going through a second apartment door.

Gonnering found Zimmermann, cold and unconscious, 50 minutes after her 911 call at their apartment on West Doty Street.

According to the documents, he told authorities, "She was the nicest person ever. Who would do this?"

The warrants said he found her "cold, her fingers stiff" and with "blood on her face."

Other search warrants stated that an autopsy on Zimmermann revealed she died of "complex homicidal violence," specifically multiple sharp force trauma wounds and multiple blunt force trauma blows. Nearly half of the total number of these multiple stab wounds penetrated Zimmermann's heart, according to the warrants.

One document said the stab wounds were inflicted with a weapon with a blade 2 to 5 inches long. A weapon has not been discovered.

The documents also showed that many items were recovered from the slaying scene, including numerous knives, blood samples and bloody women's slippers. But the warrants said there was no blood at the scene from the killer. The warrants said that items a thief might want, including two purses, a wallet, an iPod shuffle, a diamond ring and digital camera were left.

The warrants also said that DNA from another person was found on Zimmermann's body. Warrants were executed on several suspects, but they were all cleared, according to the documents.

Zimmermann's aunt, Kim Heeg, of Marshfield, told WISC-TV that the new details are "very painful" for the family. She said the family said it feels like "an invasion" to have the "world" get all the information along with them and that they have no comment right now.

District Attorney Brian Blanchard on Tuesday told WISC-TV that it was an "oversight" that the records were not sealed for another period of time, but that they would have been released sooner or later anyway. He said the responsibility to keep them sealed was shared by his office and the Madison Police Department.

He said he's waiting for more information before deciding whether to release the 911 phone call from Zimmermann. But he said the final decision is up to the county.

The Madison Police Department released a statement Tuesday saying that investigators would have preferred the search warrants remain sealed, but they don't believe the information will jeopardize their case because the investigation has advanced since Zimmermann's body was found in April.

Police said that much of the information contained in the documents is dated, but they said the details are "difficult, sad and troubling."

The statement said detectives "remain focused, and are making progress in tracking down Brittany's killer/killers." It said the department remains "committed to solving this case" but also asks for patience from the public because "resolving stranger homicides is often time intensive."

A reward fund for information leading to the arrest of the person or persons responsible for Zimmermann's death is at $14,000. Police said there is also up to $1,000 in Crime Stoppers' money available in this case, and anyone with information is urged to call Madison Area Crime Stoppers at 608-266-6014.

The documents also include a detective's description of Zimmermann's actual 911 call, but the call itself hasn't been released. WISC-TV, along with several other media outlets in the state, have filed a lawsuit for the tape's release.

On Tuesday, the group asked Judge Richard Niess to order immediate release of the call and other documents. An attorney for the media group said the public was "apparently misled" as to the importance of keeping information secret or, at least, the need was greatly overstated.

In response, Dane County lawyers said there is now a stronger public interest to release the details but they are not privy to criminal investigation and that the court is best to decide the matter.

In addition to the audio of the 911 call, the media group has requested the full investigative report into how the call was handled. Dane County officials have argued doing that could jeopardize the investigation.

A hearing has been schedule for Dec. 10.

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