THOUSAND OAKS, Calif. (AP) _ Nearly 1,000 people packed a funeral Mass for a college couple slain after being abducted outside an apartment, allegedly by men who wanted to steal their car and eliminate witnesses.

Meanwhile, court documents said three of the four men arrested in the slayings have confessed to the killings and implicated the fourth as the triggerman.

Brian Edward Harris, 20, and Michelle Anne Boyd, 18, whose bodies were found Sunday, grew up in suburban Thousand Oaks and attended the same high school. They went to different colleges.

The Rev. Terry Franklin said at the Mass on Thursday at St. Paschal Baylon Catholic Church that he had asked himself why the two were killed.

''There is no person on Earth that has the answer of why, except one: Jesus Christ,'' he said.

''Brian and Michelle were certainly two people who loved life, enjoyed life. They were in love, and that love spread out to everyone around them,'' Franklin said.

Harris, a student at California State University-Northridge, and Ms. Boyd, of the University of California-Los Angeles, were last seen alive Sept. 30 as they walked toward Harris' car outside Miss Boyd's apartment in Westwood Village near UCLA.

Their bodies were found near the San Diego Freeway. They had been shot in the head, police said. The car was found Oct. 1, gutted by fire.

Authorities believe four men stole Harris' car and then killed the couple to eliminate witnesses. Three of the men reportedly belong to street gangs.

Stanley Bernard Davis, 23, Damon Layte Redmond, 19, De Andre Antwine Brown, 21, and Donald Roy Bennett, 21, have pleaded innocent to charges of murder, robbery, kidnapping and auto theft. They are being held without bail in county jail.

The murder charges against Davis and Redmond include allegations of special circumstances which, under California law, could result in the death penalty or life imprisonment without parole if they are convicted.

Documents filed Thursday in West Los Angeles Municipal Court said Redmond, Brown and Bennett told police Davis shot the couple with an Uzi semi-automatic weapon. The weapon was found under a bed in Brown's home, the documents said.