Video shows him covering his mouth and saying "goddamn it".
Moon, who had been a federal agent for more than 20 years, was fired when the allegations first surfaced.
The police report into the case revealed other disturbing details, with Moon's girlfriend telling investigators that he threw out his computer when he learned that police were hunting for him.
He also had a video of "girls doing gymnastics" in an email he sent to his own Gmail account.
Moon pulled the underwear from the hamper. Photo / ABC15
Moon spotted the camera on his second visit to the bedroom. Photo / ABC15
Moon was indicted on two counts of felony trespassing with sexual motivation. He later cut a deal with prosecutors and pleaded guilty to misdemeanour trespassing, ABC15 reported.
"This is by far the stupidest thing I've ever done in my life," Moon said in court during his sentencing, where the judge took into account Moon's prior military service and police work when agreeing to a deal that will see him serve his probation unsupervised.
The sentence was passed despite the girl's father telling the court he had increased security at home following the incident.
"What if he comes back?" the dad said. "What if he tries to hurt us or our daughter? What if he loses his job and has nothing else to lose?"
Prosecutors also argued for supervision, with Deputy County Attorney Marcus Beecher saying: "The actions by the defendant, in this case, show a need for evaluation, show a need for potential treatment, and that's going to go unnoticed, untreated if there's no evaluation done in this case."
The judge's decision means that Moon can apply for his trespassing charge to be set aside after he completes his probation.
