The trial has been delayed for the Minnesota man accused in a string of mailbox pipe bombings in Iowa and across the region.Twenty-one-year-old Luke Helder -was- scheduled to face a jury in November, but the trial has been pushed back to next spring, with a start date of April 14th. Helder is accused of planting 18 pipe bombs in mailboxes in Iowa and four other states last spring, injuring six people. Helder’s first trial will be in U-S District Court in Cedar Rapids. He also faces charges in Illinois and Nebraska. Helder was allegedly trying to make a smiley face design with the location of his bombs. His defense attorney will reportedly use an insanity defense.