In the early morning hours after his arrest, a District man accused of murdering police Sgt. Joseph M. Cournoyer last January told police he had struggled with Cournoyer, but said his gun went off accidentally.

Sylvester R. King Jr., in a videotaped statement shown yesterday in D.C. Superior Court, told police after his arrest that he was "sorry" that the shooting had resulted in the officer's death. King, 36, is charged with first-degree murder and armed robbery in the slaying of Cournoyer, 30, a six-year member of the police force.

After listening to the barely audible statement in a darkened courtroom, Chief Judge H. Carl Moultrie I ruled that the videotaped statement could be introduced at King's trial, scheduled to begin today.

Moultrie rejected claims by King's attorney that the statement was given involuntarily because King feared for his safety in police custody.

King said in the taped statement that on Jan. 29 he was involved in a robbery at Murry's Steaks at 4061 Minnesota Ave. NE and that subsequently he boarded a bus at a nearby Metro station. Moments later, Cournoyer got on the bus, King told the two officers conducting the interview.

Cournoyer spotted King, patted him down, and told him to get off the bus, King said on the tape. As the two men left the bus, King said, a struggle ensued during which a handgun he was carrying fired, striking the officer.

When asked on tape by one of the detectives if he had intended to shoot Cournoyer, King shook his head and said, "No."

"I'm sorry it happened," King said.

Two other men who police said participated in the robbery at Murry's Steaks have pleaded guilty to second-degree murder charges. King, if convicted on the first-degree murder charge, would face a mandatory sentence of 20 years in prison before he would become eligible for parole.

King was on parole on an earlier burglary conviction at the time of Cournoyer's death, and has several previous felony convictions, according to court records. Assistant U.S. Attorney Alan Strasser told Moultrie yesterday that King is eligible for a stiffer sentence if he is found guilty because of the prior convictions.

In asking the judge to suppress the statement, King's lawyer, Richard Greenlee, cited the early morning hour of King's arrest and his repeated mention of concern that he might be hurt in police custody.

King was arrested about 3 a.m. on Jan. 31 at the apartment he shared with his mother on Jay Street NE, and questioned until about 5 a.m. Greenlee noted that at one point on the videotape, King said he was "scared as hell."

Strasser, however, emphasized that King had been informed of his constitutional rights, and said that he appeared calm on the tape.

"There is no question in the court's mind . . . that the defendant voluntarily made the statement," Moultrie said in refusing to suppress the statement. Moultrie also cited a telephone conversation King had with his mother after his arrest in which King, according to a police detective, said the police had been as "fair as could possibly be."

In the videotaped statement, King said he tossed away the gun after the shooting and hid for several hours before returning to the Jay Street apartment. "I wanted to turn myself in, but I was scared," King said in the taped statement.

After giving his statement King called his mother, a detective who questioned him said yesterday in court. "Don't cry, mamma," the detective recalled King saying. "I didn't mean to shoot him. The gun went off accidentally."