Officer Krystal Rivera was excited to celebrate her daughter's 11th birthday this weekend. But Rivera's life was tragically cut short late Thursday, when she was fatally shot in the back by a bullet fired by another officer.

Krystal Rivera, the Chicago police officer shot and killed in Chatham, was a loving mother, friend, and devoted police officer who cared deeply about protecting the community.

Late Friday, the Chicago Police Department said that another officer's gunfire "unintentionally struck" the 36-year-old Rivera during an encounter with an armed suspect in Chatham.