A Halloween trick backfired on 13 teenagers after they egged an unmarked patrol car about 8 p.m. Friday, police said. The teenagers, dressed in black, were walking along Horizon Drive, a Hernando County sheriff's report said. As the deputy drove up, they splattered his car with eggs, striking the hood, windshield, side windows and rear fender, the report said. When the deputy identified himself, the teenagers ran down back streets and between houses. Six of them were caught and arrested several blocks away. Deputies arrested the others at 9302 Spring Hill Drive a short time later. The teenagers told the officers they had planned to throw the eggs at houses and cars, the sheriff's report said. They were taken to Hernando County Jail and charged with criminal mischief and conspiracy to commit criminal mischief. Twelve of the teenagers, who are juveniles, were released to their parents. Joseph M. Smith, 18, of 3206 Ambassador Ave., Spring Hill, was also charged and released. Deputies seized about 20 dozen eggs in cartons in a brown plastic bag.