A Jonesborough man is sentenced to 10 years in prison after he pleaded guilty to sexual activity with a minor.According to a release from the Department of Justice, William Charles Ellis, 51, was sentenced on April 15 to 120 months in prison, with 15 years of supervised release to follow.Ellis will also be required to register as a sex offender and comply with those conditions following his release.The release states Ellis’ charges stem from an investigation in August 2019, during which Ellis used an online dating app to communicate with a person he believed was a 15-year-old girl.Instead it waas an FBI agent.