RENO, NEV. -- A man testified Thursday that he found a blasphemous statement when a song by the British rock group Judas Priest was played backward, during a trial in which the plaintiffs allege that the music drove two youths to shoot themselves.

Portions of the band's "Stained Class" album were played in a packed courtroom as William Nickloff Jr., a former producer of subliminal self-help tapes, testified that he found an obscene phrase directed at Jesus Christ recorded backward in the song "White Heat, Red Hot."

Although the phrase, played repeatedly, seemed to be distinct, attorneys for CBS Records and band members characterized the evidence as "strictly an illusion," and vowed to offer proof when they present their case later in the trial.

The testimony came on the fourth day of trial in the case against the band and record company by the families of the two youths.

Raymond Belknap, 18, held a sawed-off shotgun to his chin and died instantly from a single blast two days before Christmas 1985.

James Vance, 20, blew away the lower portion of his face. Horribly mutilated, he lived three more years, eventually dying of complications from his injuries and a reaction to medication.

The families claim that subliminal messages on the album touting Satanism and suicide drove the two to shoot themselves in a church playground.

On Thursday, Nickloff testified he recorded the 1978 "Stained Class" album onto a multitrack tape system, then played the tape backward to detect the alleged hidden messages. He was to be cross-examined later yesterday.

Along with the anti-Christ message that seemed to be audible on "White Heat, Red Hot," he also played backward a portion of the song "Stained Class," which revealed the audible words "sing my evil spirit."

Outside the courtroom, band guitarist Glenn Tipton told reporters, "If you choose a nursery rhyme {and play it backward}, you'll find swear words also."

"You can make anything out of anything," he said.

Defense attorneys said Nickloff's degree in marine biology doesn't qualify him to pass judgment on the music's alleged content.

"A marine biologist with absolutely no credentials is threatening the artistic freedom of Americans," Tipton said.

Ken McKenna, representing Belknap's family, expressed confidence that the demonstration confirmed the families' case has merit. He said the families need to prove that subliminal messages exist and that they played a part in the youths' shooting themselves.

"I think we've demonstrated they exist," he said.

The defense maintains the fates of Belknap and Vance were predestined by alcohol and drug abuse, turbulent family lives, poor academics and brushes with the law.

Although the backward messages seemed to be clear, courtroom observers were unconvinced about the existence of a supposed subliminal message saying "do it" on the song "Better by You, Better Than Me" that allegedly prompted the suicide pact. Unlike the other alleged messages discussed Thursday, this one was forward, not backward.