A furlough program created by the state legislature in 1971 allowed prison superintendents to approve furloughs of up to thirty days for inmates to live outside the prison. By February 1972, more than 2,000 furloughs had been approved across the state. A handful of inmates had failed to return, but there had been no major problems. Then, on a Saturday evening early in the month, state trooper Frank Noble made what started out as a routine traffic stop. An inmate from Walla Walla, out on his second furlough, was behind the wheel. When Noble approached the car the inmate pulled a gun and shot three times. Noble died at the scene and the inmate was arrested within the hour. Furlough requirements were tightened and the program continued.