In this Feb. 3, 2015, photo, Marilyn Mosby, right, Baltimore City State’s Attorney, holds a press conference regarding the Phylicia Barnes case. At left is Deputy Chief Michael Schatzow. Baltimore’s chief prosecutor is 35 years old, has been on the job for less than four months and is about to take on the biggest challenge of her career weighing the evidence against six police officers in the death of Freddie Gray and deciding whether they deserve to be criminally charged. (Algerina Perna/The Baltimore Sun via AP)