From Secret Service Twitter Account:
At approximately 5:53 PM today, a 51 year old male approached a U.S. Secret Service Uniformed Division officer who was standing at his post on the corner of 17th Street and Pennsylvania Avenue N.W. near the White House Complex. The suspect approached the officer and told the officer he had a weapon. The suspect then turned around, ran aggressively towards the officer, and in a drawing motion, withdrew an object from his clothing. He then crouched into a shooter's stance as if about to fire a weapon. The Secret Service officer discharged his weapon striking the individual in the torso. Officers immediately rendered first aid to the suspect and D.C. Fire and EMS were called to the scene. Both the suspect and the officer were transported to local hospitals.
The White House Complex was not breached during the incident and no Secret Service protectees were ever in danger.
The Secret Service Office of Professional Responsibility will be conducting an internal review of the officer's actions. The Metropolitan Police Department was contacted to conduct an investigation.