BUFFALO, N.Y. - Horrified motorists sprang from their cars Friday to stop a woman who was repeatedly slamming her 7-month-old daughter onto a concrete sidewalk, police said. The baby later died of massive head trauma. Kirsten Vanderlinde, 36, who receives mental health care as an outpatient, was charged with second-degree murder in the death of Melissa Vanderlinde-Berst. Police had checked on Vanderlinde twice shortly before the attack. A neighbor said she had called a crisis intervention center two days earlier, after Vanderlinde, fearing she was a bad mother, asked her to take custody of the child.