CEDAR RAPIDS, Iowa (AP) – A former college student accused of planting pipe bombs in a “smiley face” pattern across the Midwest nearly two years ago was declared incompetent to stand trial Thursday by a federal judge.

Luke Helder, 22, was ordered to return to the Federal Medical Center in Rochester, Minn., where he will undergo another round of psychological evaluation to determine if he is a risk to others. U.S. District Judge Mark Bennett could free him if he is found not to be a significant risk.

Helder was caught after a nationwide manhunt in May 2002, when 18 pipe bombs and anti-government letters were placed in mailboxes in Iowa, Illinois, Nebraska, Colorado and Texas.

Six pipe bombs exploded in Iowa and Illinois, injuring four letter carriers and two residents.

After his arrest outside Reno, Nev., Helder told authorities that by scattering the bombs across the country, he was trying to draw a “smiley face” on the map.

Helder, in court for the first time since his June 2002 arraignment, turned and smiled at his parents several times before and after the hearing, but otherwise sat calmly through the proceedings. Helder’s parents declined to comment afterward.

Helder, a former art student at the University of Wisconsin-Stout in Menominee, Wis., has pleaded innocent to federal charges of using a pipe bomb in a crime of violence and destroying property used in interstate commerce – mailboxes. The charges carry a life sentence.

In the months after Helder’s arrest, his attorney, Jane Kelly, filed court papers declaring her intention to use an insanity defense.

If Helder is declared competent at some point, the federal charges remain and could be reinstated.

AP-ES-04-01-04 1818EST