In a telephone conversation yesterday afternoon, Cook told a reporter that he had been prepared to testify. When asked why he did not, he said simply: ''I don't feel I can comment on that right now."
Earlier in the day, Cook's lawyer, Daniel-Paul Alva, told Common Pleas Court Senior Judge Albert F. Sabo: "There is no reason I can offer the court as to why he's not here."
Even though both sides gave their final arguments on Monday, Sabo had allowed the hearing to continue one more day to accommodate Cook's testimony.
Alva said that when he met with Cook for 15 minutes Monday morning, "he was anxious to testify and emotionally unstable."
After it was clear that Cook would not show up, Sabo recessed the hearing - while also leaving open the possibility that Cook could testify anytime before he rules on the defense petition for a new trial.
Sabo gave no indication when he might rule, but prosecutors said they anticipated that the decision could come within a week.
The Abu-Jamal defense team appeared disappointed and deflated by Cook's absence.
"Billy Cook was an important witness," said lead defense attorney Leonard Weinglass. "He told us he has favorable testimony to exonerate his brother. To lose this is hurtful."
Prosecutor Charles "Joey" Grant said that he never expected Cook to show up, and that the possibility of his appearing was raised only to answer media questions about why Billy Cook was not testifying.
"They knew Billy could explode on them, and I don't think they really wanted him to testify," he said.
Pam Africa, a MOVE member who heads the Concerned Family and Friends of Mumia Abu-Jamal, said she wasn't surprised that he didn't appear. Noting the large contingent of armed police officers in the hallway outside the courtroom Monday and yesterday, she said: "He's got friends. He could be checking with them, 'Is it cool to come in?' "
Though the defense said it was disappointed that Cook did not show, Africa said his testimony "wasn't that important," because other witnesses during the appeals hearing have testified they saw someone other than Abu-Jamal kill Faulkner. Prosecutors have attacked those accounts as inconsistent with the physical evidence.
In court Monday, defense attorney Rachel Wolkenstein reported that Cook - who did not testify in Abu-Jamal's 1982 trial - told her in Pittsburgh last week that his brother had not killed the officer. He told her that another black man was in his car, she said, but that he would not identify the man.
That report conflicts with an unsigned statement Cook gave to police the night of the shooting, Dec. 9, 1981, in which he said he did not see who shot Faulkner. He said he was searching for papers in his glove compartment when he heard shots and turned around to see the policeman and a black man - who, unknown to him, was his brother, Mumia - lying on the street.
Prosecutor Grant charged that Wolkenstein's recounting of Cook's alleged statement in court was "an obvious tactic to get out their version of events without Cook being cross-examined."
Maureen Faulkner, widow of the slain officer and the recipient of increasing hostility from some of Abu-Jamal's supporters, was relieved that Cook did not testify and that the hearing had come to an end.
"I believe that Sabo will review the transcripts and will give a ruling that abides by the laws of the land," she said.
Reflecting some of the hard feelings created by the case, when prosecutor Grant at the end of the hearing approached Wolkenstein to shake hands, she refused to do so.
What Cook, a street vendor in 1981, saw the night of Faulkner's murder has always been a mystery, as has his silence. Cook did not testify at his brother's 1982 trial. Cook's attorney, Alva, said Abu-Jamal's trial attorney did not call Cook as a witness then.
Abu-Jamal's attorney and family members have said that Cook has been homeless in recent years, appearing from time to time, then dropping out of sight.
On Aug. 17, while his brother's appeal hearing was in progress, Cook appeared at a rally in a Philadelphia church. Last week, he surprised the defense by showing up at a hearing in Pittsburgh on his brother's civil lawsuit against the state prison system.
According to all accounts, Faulkner stopped Cook's car for a traffic violation at 13th and Locust Streets at about 3:30 a.m. on Dec. 9, 1981, and the two got into a physical altercation. During Abu-Jamal's 1982 trial, the prosecution argued - and the jury agreed - that the former radio reporter happened upon the scuffle, ran up behind the officer and shot him in the back. After Faulkner fell to the ground, Abu-Jamal stood over him and shot him in the face, prosecutors charged. Abu-Jamal was wounded by a bullet fired by Faulkner.
Weinglass, like Alva, said he did not know why Cook decided not to come to court. He speculated that Cook feared being arrested on two outstanding bench warrants on theft charges. He asked Sabo yesterday to protect Cook from arrest, saying Cook "might come in" if he felt certain he would not be jailed. Sabo said that by law, he could not make such a ruling.
Under an agreement reached by prosecutors and Alva on Monday, Cook would not face arrest when he appeared in court, but would turn himself in immediately after testifying.
Grant said Cook would not have been jailed if he appeared, at least not immediately and possibly not at all. Under the pre-release system set up in the prison-cap case in federal court, defendants who have failed to appear for hearings are simply given subpoenas to show up at some future date.
Weinglass and Alva said Cook is very fearful of police. Alva said Cook told him of being harassed by police in the years since Faulkner's murder.
Weinglass said Cook lives in a dangerous environment where "a lot of people will carry out what they perceive or misperceive would curry favor with police. He's a homeless person. He lives on the street."
Alva said that Cook, whom he had not seen in eight or nine years, looked fine physically when he met with him Monday. But "the way he answered questions and was talking to me" suggested that he might be "emotionally unstable," Alva said.
"It was clear he had not purged whatever devils he has inside himself," Alva said. "A lot of his answers were not responsive."