A 21-year-old college student accused of planting pipe bombs across the US Midwest planned to arrange the devices in the shape of a giant "smiley face" stretching across the map of the United States.
Nevada police said Luke Helder, an art student at the University of Wisconsin-Stout, divulged his design afterhe was arrested outside Reno.
"Immediately after he was taken into custody, in a conversation with one of my deputies, he said something to the effect when he is finished he wanted to make a smiley face," said Sheriff Ron Skinner.
Helder is accused of putting 18 pipe bombs in rural mailboxes in five states - Illinois, Iowa, Nebraska, Colorado and Texas - injuring six people.
