A Chicago police officer was unintentionally shot and killed by her partner after they chased a suspect into an apartment and encountered another person with a rifle, officials said. Krystal Rivera, 36,

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.

The Chicago police officer killed in Chatham was identified as 36-year-old Krystal Rivera, a mother and a four-year veteran of the police force.