After the man who killed five people and injured seven others at the Annapolis, Md.-based Capitol Gazette newsroom obscured his identity, authorities used facial recognition technology to identify him. 

The man, described in reports as a white male wearing a black t-shirt and olive pants, was taken into custody at the scene but authorities said he carried no identification and had damaged his fingers, prompting law enforcement to use facial recognition software to identify him, NBC News reported

William Krampf, the acting police chief of Anne Arundel County, Md., told reporters Thursday evening that he had no knowledge of the use of facial recognition technology by investigators.