Officers Are Heard Laughing on Tapes : King case: One also was recorded telling a dispatcher that the victim had numerous head wounds.

Seconds after Rodney G. King was struck and kicked by police on a Lake View Terrace street, several Los Angeles policemen began laughing as Officer Laurence M. Powell struggled to describe King’s “numerous head wounds” over the police radio, according to evidence presented Wednesday in the trial of four policemen charged in the assault.

The police radio conversation and a computer message sent that night by Sgt. Stacey C. Koon--in which Koon said King had just been beaten “big time”--were brought up by prosecutors in an attempt to bolster their contention that King was bashed over the head with a baton swung by Powell.

In addition, they called to the witness stand a Pacifica Hospital emergency room physician, who described giving King 20 stitches to close facial and head cuts after he was taken to the hospital by ambulance early on the morning of March 3, 1991.

“He had several bruises in the scalp at the right side of the head,” the doctor testified. “He had bruises, and the nose was bleeding. There were bruises in the chest. There were bruises in the back. And there were bruises on the leg.”

But defense attorneys, primarily Michael Stone, who represents Powell, attempted to cast doubt about exactly what caused the head injuries. Stone contends that Powell hit King in the shoulder area--not the head.

And when Stone questioned Dr. Antonio Mancia about King’s head wounds, the doctor said the injuries could have been the result of King’s falling and hitting his head on the pavement that night.

Mancia also told Stone that he never really found out that night how King was injured. “I asked him what happened,” the doctor testified. “He didn’t answer me.”

An audiotape of the LAPD radio frequency was played several times in the courtroom Wednesday. The tape begins with California Highway Patrol officers, who were pursuing King in a high-speed chase in the San Fernando Valley, requesting Los Angeles Police Department assistance. The tape ends about 15 minutes later, after King is beaten, an ambulance is ordered, and a tow truck is summoned to remove King’s car.

On the audiotape, an officer can be heard describing the beating. And on the amateur videotape of the incident, played again in court Wednesday, Powell can be seen speaking into his hand-held radio.

Powell is shown on the videotape grabbing his radio just seconds after he stopped striking King with his baton, and as other officers swarmed around the motorist and handcuffed and hogtied his hands and feet.

“We need an RA (rescue ambulance) at Foothill and Osborne” streets, Powell is heard saying into the radio microphone.

Referring to King, Powell says the officers had a “victim of ah, . . . ah . . . “ As Powell seems to falter, a voice in the background says, “beating.”

At that point, laughter can be heard, and Powell says, “Yeah . . . numerous head wounds.”

LaShon Frierson, an LAPD radio communications official, then testified that it was “unusual” to hear such “laughing and giggling” on a police radio. Frierson also said it was unusual for a police officer to pause because he needs help describing a crime scene he has just witnessed.

Prosecutors said they plan to introduce evidence showing that Koon, who shot King with an electric stun gun, sent a computer message advising the Foothill police station that his unit had been involved in an incident involving the use of force.

Koon sent his message just two minutes after Powell radioed about the beating.

“U (unit) just had a big-time use of force,” Koon wrote in the computer message. “Tased and beat the suspect of a CHP pursuit big time.”

According to Deputy Dist. Atty. Terry White, the lead prosecutor in the case, Koon’s message was answered at the Foothill station with this response: “Oh, well, I’m sure the lizard didn’t deserve it. Ha, ha.”

However, Koon’s attorney, Darryl Mounger, argued that there was no proof that Koon ever saw that message. And Judge Stanley M. Weisberg ruled that only Koon’s computer message, and not the response, can be presented to the jury when the trial resumes today.

Koon and Powell, along with Officers Theodore J. Briseno and Timothy E. Wind, have pleaded not guilty.

In another development Wednesday, the judge announced that attorneys on both sides of the case will not speak to the media until the trial is over.