Ad asked for girl willing to engage in sexual activity. An undercover officer answered it

The online ad asked for a young girl willing to touch herself in front of a 61-year-old man.

An undercover officer responded, posing as a 13-year-old girl and offering to meet and have sex.

They arranged to meet at a Pierce County location July 30.

The man sent a photo of himself at the meeting spot, but the meeting didn’t happen that night because of “another case that was being conducted at the time that required all of the available officers to be involved,” court documents show.

Sexual messages continued to be exchanged for the next month, and the undercover officer posing as the girl set another meeting for Thursday.

Surveillance units watched as the man arrived and took him into custody.

Police found $25 in his pocket, which they believe he planned to give the girl in exchange for sex.

On Friday, Pierce County prosecutors charged him with attempted second-degree child rape and communication with a minor for immoral purposes.

Prosecutors said they are deciding whether to add a charge of commercial sex abuse of a minor.

The investigation is ongoing and detectives said they plan to check text messages on the man’s cell phone.