Officers were called to the 1100 block of Princeton Avenue in Lawncrest early Saturday morning.
Someone had called 911 to report a man armed with a knife. When second district officers arrived, they say the suspect was holding a knife to his throat. Officers told the man to put down the knife.
When officers requested a taser to subdue the man, they say he yelled at them and charged at them with the knife. Officers reacted by shooting the man once in the chest.
The suspect is now hospitalized in critical condition.
The officers involved in the call are assigned to desk duty pending an internal investigation into the shooting.
Investigators have not identified the man shot, or said why he put the knife to his throat.
