A Mexican national who was in the U.S. illegally has been arrested and is being held on $1 million bail after allegedly crashing his vehicle into a Washington State Patrol trooper and killing him. Trooper Christopher M. Gadd, 27, was watching for speeding and DUI drivers, when he was struck and killed in a three-vehicle crash on Interstate 5 around 3 a.m. Saturday. An investigation into the crash found an SUV being driven by 33-year-old Raul Benitez Santana was heading southbound on the interstate when the vehicle veered onto the shoulder and struck the trooper’s patrol car.