The Pottawattamie County Sheriff’s Office says a man who showed up at the Pott. County Sheriff’s Office Thursday afternoon to make a required address change with regard to the Sex Offender Registry, was taken into custody on a warrant out of Nebraska. Authorities say 36-year old Christopher Lee Karsten, of Council Bluffs, was arrested for Failure to Comply with the Iowa Sex Offender Registry, and on Nebraska warrants for Domestic Violence Terroristic Threats and Use of a Weapon to Commit a Felony. Since authorities in Nebraska said they wanted to extradite Karsten, a charge of Fugitive from Justice was also applied. He was being held without bond in the Pott. County Jail.