As part of an ongoing child predator operation, Aurora police arrested a Greeley man Wednesday on suspicion of trying to sexually assault who he thought was a 12-year-old girl.

Daniel McCarthy, 39, faces charges of internet luring of a child and attempted sexual assault on a child after he allegedly tried to persuade the “girl” to run away from home and went to meet up with her for sex, according to a Friday news release from the Aurora Police Department.

The supposed 12-year-old girl was actually an undercover officer, planted during an online operation that used social media advertisements designed to identify and arrest predators on March 27-28, according to the release.

McCarthy responded to the advertisement on March 29 and had been talking to the “girl” for over eight months, trying to convince her multiple times to run away from home and live with him in Greeley.

Police arrested him on Wednesday when he arrived at a pre-planned location to allegedly meet up with her for sex, according to the release. Authorities also found a loaded handgun in the front seat of the vehicle McCarthy arrived in.

The operation was a collaboration between Aurora Internet Crimes Against Children detectives, as well as the Boulder County District Attorney’s Office, the Longmont Police Department and Homeland Security Investigations, according to the release.

Anyone with more information about McCarthy is asked to contact Metro Denver Crime Stoppers at (720) 913-7867. Tipsters can remain anonymous and could be eligible for a reward of up to $2,000.