A hardware store receipt led authorities to the suspects who allegedly set off homemade explosive devices Monday night in the east metro communities of Lake Elmo and Afton.

Nicholas Thole, 29, of Woodbury, and his cousin Seth Slaikeu, 40, of Hudson, Wis., each were charged with aiding and abetting in the possession, making, transporting and storing an explosive or incendiary device, according to charges filed in Washington County District Court.

Both suspects were arrested Tuesday night and booked into jail.

According to the charges, police responded about 8:50 p.m. Monday to several calls about an explosion in the vicinity of 27th Street Court in Lake Elmo. Sheriff's deputies found a device made of galvanized pipe, blue painter's tape, caps and a plastic bottle had exploded on the lawn of a residence, with parts landing on the street and other lawns.

While investigating the bombing, deputies were called to the intersection of Oakridge Trail and Oakridge Circle in Afton and found a detonated device in the street. A deputy found a galvanized pipe nearby and saw a black Crown Victoria with push bumpers leaving the area, the charges said.

A detective returning to the area the next day found a UPC barcode near the blast site and traced it to an Ace Hardware store in Woodbury. The barcode had been scanned at 8:20 p.m. Monday for a transaction made by Thole, according to the charges, and cameras captured a black Crown Victoria leaving the parking lot 10 minutes after the purchase.

Police learned that Thole owned a black Crown Victoria and saw a vehicle matching that description coming and going from a residence in Woodbury. They also learned that the vehicle spotted during surveillance was registered to a residence about 200 yards from where the Afton detonation occurred, the charges said.

Thole denied the purchase, according to the charges, but when confronted with the receipt admitted he bought the items at the hardware store and drove to Slaikeu's house in Hudson to make the explosives.

Authorities found Slaikeu at home, where he admitted that he and Thole made the devices in his garage and then drove back to Minnesota to set them off. They had contemplated numerous sites, including under an Interstate 94 overpass, before settling on the Afton site, the charges said.