MADISON, Wis. -

A federal judge has dismissed a civil rights lawsuit filed by a man exonerated in the 1980 rape and strangulation of a University of Wisconsin-Madison student.

U.S. District Judge Barbara Crabb said Ralph Armstrong failed to identify the people or agencies who he claims violated his civil rights. Armstrong, acting as his own attorney, only named the state of Wisconsin as a defendant. Crabb said the state as an entity cannot be sued.

Armstrong's conviction in the death of Charise Kamps was overturned in 2009 after a Dane County judge found prosecutors violated a court order about the testing of certain evidence. The State Journal reported the 60-year-old Armstrong in imprisoned in New Mexico, where he's being held for violating parole on a different crime.