Early on the morning of Dec. 20, 1986, a baby-faced white teenager returned to a neighborhood birthday party after encountering three black men whose car had broken down on a deserted stretch of Cross Bay Boulevard in Howard Beach, Queens.

“There’s niggers on the boulevard,” the teenager, Jon Lester, a transplanted English 17-year-old, was quoted as telling the beered-up partygoers, adding (and inserting an expletive), “Let’s go kill them.”

According to later courtroom testimony, the 5-foot-4 Mr. Lester was a ringleader of a dozen white teenagers who jumped into three cars and ambushed the black men at a nearby pizza parlor.

The gang mercilessly chased one man, Michael Griffith, 23, who escaped by running onto a busy highway, where he was struck by a car and killed. Another man in the car, Timothy Grimes, outran his pursuers. But they caught and savagely beat the third black man, Cedric Sandiford, 36, with a baseball bat, a tire iron and a tree limb.