As police in the St. Louis suburb of Ferguson seek alternatives to the sort of lethal force that led to Michael Brown’s death, they’re testing a new device that attaches to a handgun barrel and is designed to turn a bullet into a projectile intended to stun but not kill. Mayor James Knowles III said Wednesday that a few Ferguson officers will test the device, known as the Alternative, at a shooting range Thursday. But Knowles said the department is early in the evaluation stage and the city has not decided whether to purchase the device. […] The Alternative is...