Police in Oshkosh said 21-year-old Michael T. Philbin of Ripon was last heard from around 2 a.m. Sunday. He had been visiting friends in Oshkosh that evening. He was reported missing on Sunday evening.
A police spokesman did not immediately return a message left Monday seeking additional comment.
A Brown County judge sentenced Michael Philbin to six months in jail in 2009 after he was convicted of sexually assaulting two young girls and two counts of battery.