A teenager from St. Paul suspected of shooting and killing a 15-year-old in downtown Minneapolis had, at the time of the incident, been on probation for a gun charge. Tashawn Powell, 17, was charged with second-degree murder Thursday after allegedly shooting Fred Ulysses Walker, 15, at a light rail station in downtown Minneapolis Tuesday evening, according to Hennepin County Attorney Mike Freeman. Metro Transit surveillance video captured the 15-year-old Walker putting his hands up before Powell shot him in the chest. Paramedics declared Walker dead at the scene after police and a Good Samaritan tried to save him. Per the...