According to police and court records, Alan Glen Smith told his roommate he wanted to invite a male friend and his two young daughters over to the apartment. His roommate says Smith wanted to give the friend a sleeping pill so he could have sex with the girls.
In response to the allegations, the Weld County Sheriff's Office arranged an opportunity for Smith to purchase Ambien - a prescription sleeping aid - from undercover officers.
Smith was taken in custody after going to a Greeley Walgreens in June to pick up the drug.
In October, Smith pleaded guilty to one count of conspiracy to commit sex assault on a child.
He will be required to register as a sex offender.