TEL AVIV, Israel (AP) _ Yitzhak Rabin's confessed assassin re-enacted scenes from the slaying in court Monday, smiling as he pointed a pistol and then was wrestled to the courtroom floor.

Yigal Amir took an active role in his increasingly unusual defense Monday, the fourth day of testimony in his trial in the Nov. 4 killing of the prime minister. Amir has said he shot Rabin to keep him from giving parts of the West Bank to Palestinians.

Amir asked the policeman who disarmed him after the shooting to re-enact the struggle and questioned other prosecution witnesses, who included the bodyguard wounded trying to save Rabin from Amir's bullets.

``I heard a shot,'' said bodyguard Yoram Rubin, who refused to look at Amir as he described how he threw Rabin to the ground after Amir opened fire following a Tel Aviv peace rally. ``I grabbed Yitzhak and we started to fall down. Then I was shot.''

In court, a smiling Amir again brandished the murder weapon. Grabbing Amir's right hand, policeman Yitzhak Yamin pinned him to the ground and pulled the 9-mm Beretta pistol from his grip.

Amir insisted that the gun fell from his hand when he was overpowered. At his request, he and the officer acted out the scene twice.

Amir has told the court that he wanted to remove Rabin from office but not necessarily kill him. That was registered as a plea of not guilty.

But Monday's testimony by Rubin _ who was struck in the arm by Amir's second shot _ indicated Amir kept shooting after Rabin was hit.

Rubin said Amir's third shot _ the second bullet that struck Rabin _ was fired after he had grabbed the prime minister from the back and the two were falling.

``I heard the third shot, and we were both lying on the ground _ me on top of him (Rabin),'' he said.

Dr. Yoram Kluger, head of the team of doctors that tried to save Rabin's life at Ichilov hospital, told the court the first shot that struck the prime minister perforated his lung and caused his death.

Earlier Monday, the Tel Aviv District Court appointed a second defense lawyer, former district attorney Avraham Pachter, to assist attorney Jonathan Ray Goldberg, an American immigrant who has stumbled over the Hebrew language in court.

Amir conducted much of the defense questioning Sunday and Monday, while Goldberg watched.

Judge Edmund Levy said he ``suspected the defendant was not receiving an adequate defense.''

But Levy apologized for his harsh comments of Sunday, when he said Goldberg was irresponsible.

``I would like to make a public apology ... If you are personally offended, I apologize,'' he said.

Another lawyer resigned as Amir's second attorney Sunday, saying he and Goldberg had conflicting defense strategies.

Amir's new lawyer, who met briefly with Amir for the first time Monday, described him as ``cold and intelligent.''

Joining the defense a day before the prosecution is expected to wrap up, Pachter said he hoped to help the case.

Amir, 25, an observant Jew, said he shot Rabin because he wanted to stop the handover of parts of the West Bank to the Palestinians, arguing the area is part of the biblical Land of Israel promised to the Jews by God. Amir has said he acted ``for the glory of God.''

Israeli news media reported Monday that police received new threats on Amir's life and that the defendant and the officers guarding him were wearing bulletproof vests. The slender Amir indeed appeared bulkier than usual Monday, and may have been wearing a vest under his multicolored sweater.