DENVER (AP) — A man suspected of leaving a backpack bomb outside a Colorado police station told an employee at the hotel where he was staying that he was in Nederland to visit an old friend who is a professor.

J.P. Farrell, a front desk agent at The Boulder Creek Lodge, says 64-year-old David Michael Ansberry stayed for about two weeks, left, and then returned. Nederland’s police chief saw someone matching Ansberry’s description leave the hotel when it was evacuated during the Oct. 11 bomb scare.

Court documents describe Ansberry as 3 feet 6 inches tall and 100 pounds, wearing a pony tail, ball cap and using crutches. They say he tried repeatedly to remotely detonate the bomb using a cell phone but failed.

Ansberry was arrested over the weekend in Chicago and faces a federal explosives charge.