Case Dropped in Damage to Empty House : Crime: Vandalism charges against three teen-agers were dismissed because the key witness disappeared.

A San Fernando Municipal Court judge dismissed felony vandalism charges against three Valley teen-agers Thursday because the key witness against them has disappeared.

Richard Byrd, 18, of Granada Hills and Kayron Kadjar, 18, and John Walker, 19, both of Sepulveda, were accused of causing $10,000 to 20,000 worth of damage to an empty Northridge house during a party there Nov. 3.

But Kevin Johnson, 21, one of the party-goers and the only witness who can identify the defendants, has been missing since December. Without his testimony, prosecutors do not have sufficient evidence to proceed with the case, Deputy Dist. Atty. Mark Aveis told Judge Stephen A. Marcus in court Thursday.

Aveis said Johnson “went underground” the day after receiving an intimidating phone call from Kadjar’s father. But Shapoor Kadjar denies ever speaking to Johnson. He said Johnson is afraid of police who threatened to beat him up if he did not testify in the case.

Shapoor Kadjar said Johnson told a private investigator that his son was not responsible for the damage, but that police officers were pressuring Johnson to testify against him.

Police arrested Byrd, Kadjar and Walker, and three juveniles on suspicion of breaking windows and kicking holes in the walls and doors of a home on Van Alden Street. Police said the youths were attending one of the large house parties that sometimes attract hundreds of teen-agers in the West Valley. But Kadjar said his son was not in the house at the time.

An advertising flyer said the party would last from “7:30 until the cops come” and that guests would be asked for $3 to buy beer and pay for a disc jockey. Police said guests were allowed in free because there was no beer or disc jockey. They said some teen-agers, angry because there was no beer or music, began to vandalize the house.