Closing Arguments Heard in Prom Night Slaying; Case Goes to Jury : Courts: Prosecutors call for a conviction of second-degree murder, while the defense asks the jury to free Paul Crowder.

A jury today will begin deciding the fate of 19-year-old Paul M. Crowder, charged with the slaying of Crescenta Valley High School basketball star Berlyn F. Cosman after a prom night party in Anaheim last June.

“We will concede two very tragic facts that are not in dispute,” Crowder’s lawyer, E. Bonnie Marshall, told the jury Tuesday in her closing argument.

“The first one is that Berlyn Cosman, a remarkable young woman by all accounts, died as a result of a gunshot wound,” she said. “The bullet struck her while she slept on a couch in the Crown-Sterling Suites. The second tragic fact is that Paul Crowder, her friend, was responsible. . . . He will be accountable for the rest of his life.”

But as the defense has maintained throughout the trial, Marshall said the death of 17-year-old Cosman was the result of a tragic accident. Crowder, she said, accidentally fired a .357 magnum pistol as he tripped in a darkened room, and because of that the jury should free him, or at most convict him of involuntary manslaughter.

Deputy Dist. Atty. Christopher J. Evans called the tripping scenario an insult to the intelligence of the jurors and “a pretty silly story.”

To have fallen in the way Crowder described, Evans said, he would have had to have the moves of the ballet dancer Rudolph Nureyev or a member of the Flying Wallendas circus aerial act.

Moreover, Evans said, at no time between the shooting and the trial did Crowder come forward with the story that he had tripped while entering the room where Cosman slept on the morning of her June 1 death.

In any event, Evans said, Crowder “had no business walking into a darkened room . . . with a cocked gun.” He asked jurors to consider convicting the high school dropout of first-degree murder, but steered them toward a second-degree murder finding.

Evans, who referred to Crowder as “a bit of a loser” whose date that night was his gun, based his call for a second-degree conviction on the concept of “implied malice,” which does not require the prosecution to prove that Crowder intended to kill Cosman when he walked into the room waving the pistol.

In her closing arguments to the jury, Marshall offered a color-coded chart that went from a small black section for guilty beyond a reasonable doubt to a broad spectrum indicating gradations of considerable doubt, which Evans ridiculed as being “right out of Madison Avenue.”

“This is not a case that will ever have a happy ending,” Marshall said, describing the three hotel rooms rented by the teen-agers as “the party room,” “the drug room” and “the quiet room,” where Cosman was slain after a long night of drinking.

“We know there were guns at this party,” Marshall said, including two brought to the hotel by Crowder and one by another teen-ager who was sleeping in the room adjoining the one where Cosman slept.

“That is not smart, that is not wise. We have not yet seen any evidence that it was unlawful,” she said.

Evans offered his own charts, including one which divided a dozen teen-age witnesses equally between those who he said lied the most and those who lied the least, or not at all.

Both attorneys picked apart the testimony of more than a dozen teen-age witnesses, many of whom acknowledged lying or misleading investigators and the grand jury about what they saw and what they did the night and the morning of the slaying.

Evans’ disdain for the party-goers, voiced throughout the trial, briefly spilled over into contempt, as he referred to “every one of those moron kids,” eliciting a short gasp from some of the courtroom spectators. He referred to another member of the social circle as a “clown” and an “idiot.”

In a break in the daylong arguments, Mark Cosman, Berlyn’s father, said that as he observed the trial each day from the front row, he felt as though he was shadowing Crowder in the last moments of his daughter’s life. He attended the trial, he said, as Berlyn’s representative.