On a slow day in 1979, Ron Stallworth, the first African-American police detective in the Colorado Springs (Colo.) Police Department, perused classified listings in the local newspaper. He noticed an ad seeking recruits to the region’s Ku Klux Klan chapter.Stallworth, in an exploratory mood, signed right up.A good-natured guy, this Jackie Robinson of the detective department devoted considerable time and energy to warding off subtle and not-so-subtle racism on his day job. He was surprised that the white alter ego he …