The Lancaster County Human Trafficking Task Force has arrested another sex offender. After receiving a tip from the FBI about 54-year old Sean Deemer of Lititz, an undercover officer posed as an 11-year old girl on a mobile messaging app. The two shared nearly 150-messages. Authorities also conducted an undercover operation pretending to be a 12-year old girl. Deemer is accused of sending and requesting lewd messages and photos earlier this year. He is in Lancaster County Prison on 350-thousand dollars bail.