Soon after Troy Graves delivered a tearful courtroom apology yesterday for the murder of Shannon Schieber, the Schieber family renewed its demands for another apology - this one from police.

Sylvester and Vicki Schieber believe that mistakes by the Philadelphia Police Department contributed to their daughter's death. In the four years since then, they say, police have not conceded any errors, nor apologized.

The Schiebers have filed a federal lawsuit against the city and police, alleging that their daughter's death could have been prevented.

"We're going to be like Shannon," Sylvester Schieber said after yesterday's court hearing. "If we have to fight until we die, then we are going to go down fighting."

Earlier this month, Graves confessed to police that he strangled Schieber, 23, a graduate student at the Wharton School of the University of Pennsylvania, on May 7, 1998, as she fought off his attack. He also said he tried to keep her quiet after a neighbor banged on the door during the struggle.

The neighbor called police for help. When they arrived and no one responded in Schieber's apartment, police left.

That, the Schiebers contend, was just one of the mistakes police made that contributed to their daughter's death.

"The Police Department did nothing wrong that night," Police Commissioner Sylvester M. Johnson said yesterday afternoon as he and District Attorney Lynne M. Abraham adamantly defended the actions of authorities.

Said Abraham: "I feel sorry for what the Schiebers believe. It's obvious that their emotions regarding the murder of their daughter have overwhelmed them."

After yesterday's hearing, the Schiebers voiced skepticism about what they had heard in court. They questioned whether parts of Graves' confession were coerced to paint a more favorable image for the city and police.

"We're greatly concerned about the death penalty being held over his head as he was putting down a confession," Sylvester Schieber said. "We want the truth on the table."

The police say Graves told them that Schieber was lifeless when he left and that he fled before police arrived. Experts disagree about whether Schieber died immediately or was alive when police arrived.

Graves could have faced a death sentence for the murder, but the Schiebers have said they did not want prosecutors to seek capital punishment.

Yesterday, the family faced a whirl of emotions. During the hearing, Vicki Schieber wept, then trembled as the details surrounding her daughter's murder were read in court.

Her son, Sean, and her husband remained solemn until prosecutors read a description of Sean finding his sister, nude and facedown on her bed. They choked back tears as the narrative became more descriptive.

Then, clearly agitated, the Schiebers turned to one another as prosecutor Arlene Fisk said police never entered Shannon Schieber's apartment that night because the neighbor told them he "would be embarrassed if they knocked the door down and there was nothing happening."

The Schiebers contend in their lawsuit that the police suggested to the neighbor that he might be embarrassed.

Father, mother and brother shook their heads in disgust as Fisk spoke. The crying gave way to outrage and the Schiebers later blasted prosecutors for adding to their pain. They said the discussion of police conduct was inappropriate for the criminal proceeding.

The Schiebers contend police also botched the case initially when they did not believe the first two victims who said they were raped in 1997. The police did not warn the community about a serial rapist after the first four attacks were linked, before Schieber's murder. And they did not process forensic evidence until after the slaying.

The Schiebers asked: How could this have happened?

They asked to speak with Mayor Ed Rendell, who refused a meeting in 1998. Yesterday, they chastised then-Police Commissioner John F. Timoney's review of police actions and lack of response.

Today, they still are asking for an apology from public officials. They want the Police Department to admit that mistakes were made, and they want authorities to make reforms to assure those mistakes are not repeated. They also want the city to pay their legal bills.

The fight will continue, Sylvester Schieber vowed after yesterday's hearing.

"We have been lied to in our lawful pursuit of information. We have been denied evidence. We have been threatened," he said. "We have been passionately seeking the truth in this case for years."

Ironically, they made peace with Graves before they could make peace with police. And, they say, they have forgiven him.

"He can still do something good with his life," said Vicki Schieber, a devout Catholic. "He can pray and there are things he can do to help others."