An on-line child pornography investigation has led police to a predatory sex offender in Moorhead. A search warrant affidavit says investigators seized two tablets, a keyboard, cellphone and CD from the home of 33-year-old Justin Worcester-Jordan. Court documents say Jordan was convicted of criminal sexual conduct for molesting a six-year-old girl in 1997. In 2006, he was convicted of another sex crime in Texas. The investigation began after the Minnesota Bureau of Criminal Apprehension received a tip from the National Center for Missing and Exploited Children. Charges have not been filed. The case is under review by the Clay County Attorney’s office.