MEMPHIS — Relatives, friends and community activists are calling for an end to violence that left an 11-year-old boy dead last week and a 13-year-old girl clinging to life after being shot in the head Monday. Melissa Robertson was struck by a bullet about 5 p.m. at a park in the Binghamton area of Memphis, police said. She was in extremely critical condition and on life support Monday night at Regional Medical Center. Robertson was struck by a bullet fired by one of two groups that had been arguing at the park, said Lt. Toney Armstrong with the department’s homicide...