The trial of accused mailbox bomber Luke Helder has been postponed again. The 21-year-old from Pine Island, Minnesota was to go on trial April 14th in Cedar Rapids, but his psychological evaluation has apparently not been completed and the trial has been postponed indefinitely. Helder is accused of planting mailbox bombs in Iowa, Nebraska and three other states almost a year ago. Six people were hurt by the explosions as Helder reportedly tried to make a smiley face on the map with bomb locations. Helder is currently in Rochester, Minnesota where he’s undergoing the evaluation to determine if he’s mentally capable of standing trial. Helder has pleaded innocent and his attorney says he’ll use the insanity defense.