Murder suspect Chander "Bobby" Matta told police he had broken up with his girlfriend and was failing community college classes last spring before the slayings of three prostitutes over the Memorial Day weekend.

"I . . . had to withdraw out of one class, out of calculus, and then the thing with my girlfriend, breaking up with her and stuff," he said.

Matta described the impulse that drove him and his personal problems during an interview with two police investigators on the day of his arrest in connection with the killings. A transcript of the interview released yesterday contained details of the slayings, which took place over a 36-hour period during the Memorial Day weekend.

"Once {the impulse} hit, just something else made me move, just drove me, like I know what I was doing, like I'd been shown how to do," Matta said in the transcript.

In the statement, Matta described a choke hold he said he used, a move he learned at a Vermont military school. He said he wrapped his right arm around the neck of each woman and pushed her head forward with his left hand.

"That causes the neck to break or it slows down the breathing, and it blocks off the blood to the head also," Matta said.

Matta said he covered each woman's head with a plastic bag to keep blood off himself.

"There was blood coming out of her mouth," Matta said in reference to one of the victims. "I didn't want to get it anywhere on me; I was real scared of that."

Matta made the statement June 10 at Alexandria police headquarters, where he was interviewed by Arlington Detective Stephen Carter and Alexandria Detective Derill Scott.

Matta, 21, is being held in the Arlington jail in the slayings of Sandra Rene Johnson, 20, Jody Marie Phillips, 16, and Sherry Kim Larman, 26.

He also has been charged with robbery in each of the cases, but in the statement denied knowledge of jewelry missing from the women.

Matta said he and Larman smoked marijuana in his car after he picked her up near the District's prostitution strip along 14th Street NW and before he drove her to his home on South Oakland Street in Arlington.

After the killing, Matta said, he changed his clothes and went to his job at USAir, then returned home several hours later. He then took Larman's body to the top level of a South Highland Street garage.

"I left her at the parking lot," he said, "I knew somebody would find her in the morning."

Matta told the investigators he developed a rapport with Phillips, whose body was found on a grassy knoll in Alexandria.

"She wanted my number, she said she really liked me," said Matta, who described how he and Phillips played with two pet parakeets Matta kept in his bedroom.

"One was flying around and . . . she helped me catch it and put it back in the cage," Matta said.

Minutes after Phillips's slaying, Matta said, he felt remorse. "She was a nice girl and everything," he said. "Didn't mean to do it with her."

Matta said that he tried to make the slaying of Johnson appear to be a robbery and that after Johnson's death early Sunday morning, he went to two religious services.

Matta's first trip to the prostitution area of downtown Washington called the Stroll occurred a month before the three slayings, he said.

The visit ended abruptly when police raided a hotel where a prostitute had taken him.

Matta's attorneys have said they will use insanity as a defense in Matta's upcoming trial, scheduled for Nov. 26.