ST. PAUL — A federal judge has dismissed a lawsuit filed by a Minnesota man who alleged authorities violated his rights when they arrested him in the fatal shooting of a Cold Spring police officer in 2012.

U.S. District Judge Paul Magnuson dismissed Ryan Larson’s claims earlier this month. Larson was arrested but never charged in the death of Officer Tom Decker.

Magnuson ruled that the law officers had “qualified immunity,” which protects public officials from lawsuits unless they clearly violated a person’s rights, and that prosecutors had absolute immunity.

Decker was killed Nov. 29, 2012, in Cold Spring. Authorities later said another man who killed himself was the probable shooter.

Larson has 30 days to appeal. He did not immediately respond to a call for comment Tuesday.