The motorist who struck and killed a New York state trooper Thursday during a routine traffic stop on Interstate 81 did so intentionally, state police said.

Almond Upton, 60, of Melrose, Fla., was charged with first-degree murder in the death of Trooper Christopher G. Skinner, 42, and arraigned in Town of Chenango Court on Thursday night... Before he came upon the traffic stop, police said, Upton sideswiped two other vehicles while speeding, causing minor injuries. Police did not say how fast he was going.

After striking Skinner, Upton continued a short distance northbound on I-81 before stopping his vehicle off the road. Upton then fled on foot, police said. After a brief search, he was tracked down by police dogs a few hundred yards into a heavily wooded area off I-81, where was he was found naked. He was taken into custody around 1 p.m.