Former fugitive attorney Stephen M. Bingham's failure to seek more facts immediately following a massacre at San Quentin prison in 1971 shows he knew he was guilty of smuggling in the weapon alleged to have started the tragedy, a prosecutor said today.

Beginning lengthy closing arguments to a Marin County Superior Court jury, Assistant District Attorney Terry Boren said that Bingham did not seek help from other lawyers who were with him when he heard news of six deaths at San Quentin and did not try to contact the woman from whom he allegedly received a pistol hidden inside a tape recorder in a briefcase.

Boren scoffed at Bingham's testimony that he went underground for 13 years because he feared he would be framed for murder, given the political climate at the time.

Boren said that because Bingham fled, there is no way now to track down "proof of the evil and corrupt men he said then, and thereafter for 13 years, were trying to frame him . . . . The truth was emerging and the defendant didn't want to be anywhere near it. He knew that the truth was not, and would not be, his ally."

Bingham, 44, a Yale graduate and son of a retired Connecticut judge, is charged with the murder of two prison guards, Frank DeLeon and Jere Graham, who were killed with the smuggled 9mm semiautomatic pistol. Noted prisoner-author George Jackson, a Black Panther who allegedly began the Aug. 21, 1971, incident by pulling the pistol from under a wig he was wearing, was killed by guards' rifle fire to end the violence. One other guard and two other inmates died of stab wounds.

Bingham turned himself in to authorities in 1984, after hiding in this country and overseas, mostly in Paris. When he surrendered, he said he thought the political climate had changed enough so that an attorney who had been associated with radical politics could receive a fair trial.

Bingham, tall and with a full shock of graying hair, sat without expression today listening as Boren wrapped up arguments in the 2 1/2-month-old trial. The defense is expected to begin its closing arguments Tuesday.

The briefcase with the tape recorder and pistol allegedly hidden inside was taken to San Quentin by Vanita Anderson, then a Black Panther Party member and legal assistant to Jackson. Jackson had become famous for a series of prison letters published in 1970 and was being held at San Quentin because of charges he had murdered a guard at Soledad prison, also in California.

Boren reminded the jurors that when guards refused to allow Anderson to visit Jackson because she had exceeded her visit quota for the month, she gave the briefcase to Bingham, who was going in to give Jackson some book manuscript pages to review.

When Bingham heard a news report that he was being sought in connection with the killings, he fled rather than seeking legal advice or inquiring as to how he could have become involved without his knowledge. "If the gun, clips and ammunition didn't come into San Quentin the way he heard it said on the news, then he had within his grasp the proof of it," Boren said. Bingham had Anderson's telephone number but did not try to call her, the prosecutor said. "What did he do about those things he thought so important? Absolutely nothing," the prosecutor added.

He told jurors there was no point in calling Anderson as a witness because she would decline to testify on the grounds she might incriminate herself -- which is what she did when the case was originally investigated in 1972.

Bingham has denied providing the pistol. He and his attorneys have argued that prison officials lied about the circumstances of Jackson's death, saying he was attempting to escape, in order to cover up an assassination plot.

This afternoon Boren played for the jury a chilling tape of an account of the incident by guard Kenneth McCray, who said he saw Jackson remove the pistol from under his wig and who survived, after being bound hand and foot, by feigning death while bleeding profusely from a razor cut on his neck.

The recording of McCray talking to investigators from his hospital bed two days after the killings includes his account of the slaying of another guard bound next to him. "There was a great amount of gasping and struggling and noise, and then a last gasp," McCray said in a slightly shaky voice.

Boren contrasted McCray's testimony so soon after the incident to Bingham's immediate disappearance. McCray testified, he said, "because he was not afraid of the truth . . . . He never ran away. He never hid. He never lied."

The trial has included 61 witnesses and more than 200 exhibits.

If convicted, Bingham could receive a life sentence.

Boren emphasized that, under the law, if Bingham were responsible for helping get the gun to Jackson then he was just as guilty of the guards' murder as if he had pulled the trigger. "The single issue in this case is whether the defendant passed the gun, the clips of ammunition and the wig to George Jackson during the visit," Boren said. "If you find that he did not, then he is not guilty of anything."