During two days of questioning by Philadelphia police in late May 2008, Joseph Vignola Jr. gave three conflicting statements about the slashing of an 18-year-old escort's throat at a City Avenue hotel.

First, he said he had nothing to do with it.

Then, police say, he blamed the attack on a "light-skinned black man" who burst into the room as he and the woman were having sex.

Finally, he tearfully confessed that he alone had attacked and nearly killed her on the night of May 28, according to police.

On Tuesday, a Philadelphia judge refused to throw out that crucial third statement, despite defense arguments that police violated Vignola's constitutional right against self-incrimination by continuing to question him after he failed a lie-detector test.

Common Pleas Court Judge Renee Cardwell Hughes ruled that Vignola, 20, legitimately waived his rights when he confessed. She said he knew by then that he was a suspect and had failed a polygraph. Moreover, he had a lawyer - his father and namesake, the former city controller - and continued answering police questions, the judge said.

During the previous two days, defense attorneys Dennis J. Cogan and Norris E. Gelman had tried to persuade Hughes to suppress Vignola's second and third statements.

Hughes threw out only the statement in which Vignola blamed a "light-skinned black man." The intruder, Vignola had said, accused the escort of cheating him, forced Vignola to straddle her on the floor and then slashed her throat.

What remained unanswered Tuesday was what triggered the alleged assault by Vignola, a young man with a prominent Philadelphia family name who had no criminal record.

Hughes set a hearing for June 17 for defense lawyers and Assistant District Attorney Robert Foster to say whether the case will go to trial or Vignola would plead guilty. Cogan declined comment.

At the close, Hughes took time to directly address the defendant as his parents sat in the audience a few feet behind.

"Mr. Vignola - you," the judge said, to ensure he knew she was not addressing his father. "You're grown and this is your decision. . . . You've got to deal with this and make a decision" about how to proceed with the case.

Vignola, a chunky, baby-faced man with dark hair, barely responded. He did not testify, but his father did.

Vignola Sr., now a consultant to financially distressed municipalities, recounted how police called him May 29, 2008, to say a cell-phone number on his account had turned up on the cell phone of the escort attacked and left for dead the night before. He told police the phone was used by his son and offered to bring him to the station.

Vignola Sr. said he was present as his son signed the formal "Miranda waiver" and agreed to answer questions.

After his son denied involvement, Vignola Sr. said they agreed to return the next day for a lie-detector test.

Polygraph results are not admissible as evidence in court.

Vignola Sr. testified that he dropped off his son for the polygraph but was persuaded by Police Lt. Thomas McDevitt to return later when the test was over.

When he did not hear from McDevitt, Vignola said he returned with his wife, Eileen, about 5 p.m.

McDevitt testified that he told the Vignolas their son failed the polygraph. After meeting with their son, McDevitt said, Eileen Vignola told him, "Go at him hard to get the truth."

McDevitt recalled the Vignolas saying "they needed to know how to deal with their son."

Vignola Sr., however, denied he or his wife said those words. He insisted he only gave permission for his son to take a polygraph, not submit to further police questioning.

Contact staff writer Joseph A. Slobodzian at 215-854-2985 or jslobodzian@phillynews.com.