An east Texas man will be spending the next decade, and then some, behind bars. A federal judge in Tyler has sentenced 46-year-old Timothy Callahan of Kilgore to 135 months in federal prison. That's eleven years and three months. Callahan had pled guilty back in November to possessing child pornography and admitted that had downloaded and viewed it using a peer-to-peer file sharing network. On his computer, investigators found more than 450 images of child pornography -- some depicting children younger than twelve. Callahan has a previous conviction for sexual assault in Gregg County, Texas.