CHICAGO (AP) - Prosecutors moved quickly to charge a white Tulsa, Oklahoma, police officer with manslaughter in the fatal shooting of an unarmed black man whose vehicle broke down in the middle of a street. Now, they have to prove it. Based on what's been made public to date, some legal experts say prosecutors may have a tough time proving officer Betty Shelby's guilt beyond a reasonable doubt. She is charged with first-degree manslaughter in the Sept. 16 fatal shooting of 40-year-old Terence Crutcher.