For the past two years, Joseph Richardson has been trying to figure out how to keep young black men with knife and gunshot wounds from turning up again with similar injuries at Prince George's Hospital Trauma Center outside Washington, D.C. Richardson is director of the Violence Intervention Research Project at the trauma center. When these men are admitted, he shows up at their rooms to ask them to take part in his ongoing study on risk factors for repeat violent injuries. Sometimes he finds them handcuffed to a hospital bed, guarded by a police officer or two. Richardson has to walk away. The patients are under arrest and off-limits to him.