A man looking to take down men responding to child prostitution advertisements posted an advertisement for child prostitution in order to rob clients at gunpoint when they arrive at the agreed upon site, according to police reports.
The imaginary pimp and his John were arrested in what police call a "vigilante sex sting operation", according to the Seattle Police Department.
Seattle police arrested the two men on Monday in a downtown hotel after the man offered a child prostitute on a popular classified website and lured the 19-year-old to his hotel room, a police spokesperson said in a statement.
Investigators say that the 28-year-old vigilante handcuffed and robbed his "John". According to police, the 28-year-old said he was a federal agent during the robbery. The 19-year-old allegedly told police he planned to buy video games from his attacker.
In talking to the police, the 28-year-old, said the 19-year-old responded to an advertisement which was published offering to sell sex with a 14-year-old, according to the police spokesperson.
The investigators argue that in the afternoon the 19-year-old, admitted he was trying to have sex with a girl, but said he believed the girl was 18-years-old.
Police arrested the 28-year-old on suspicion of robbery and false imprisonment. The 19-year-old was also arrested, although it was unclear what crime he is charged with.