It's the stuff of urban legend: As a Greyhound bus travels through Canada, a man stabs and beheads his seatmate as fellow passengers look on. Except that the horrific scene was all too real. In August, dozens of witnesses say Vince Weiguang Li, 40, attacked fellow traveler 22-year-old Tim McLean without provocation as the bus drove through Manitoba province. Li allegedly stabbed McLean several dozen times as others fled the bus. The Chinese immigrant then severed McLean's head, displaying it for other passengers to see, before he began hacking at the body. Police reports allege Li then began to cannibalize the corpse. Li remains in jail on second-degree murder charges.