The gunman, who attacked the Capital Gazette, a local newspaper in Annapolis, was engaged by responding officers within about 1 minute and taken into custody, officials from Anne Arundel County Government said.
There was no gunfire exchanged between the suspect -- described as an adult male -- and officers, officials said during an afternoon news briefing.
The suspected shooter wasn't carrying a wallet or identification and is not cooperating with authorities, officials told ABC News.
Authorities identified the gunman by using facial recognition, a law enforcement source told ABC News. The gunman had mutilated his fingers in an apparent attempt to avoid being identified, the source said.
Phil Davis, a crime and courts reporter with the Capital Gazette, said the gunman shot through a glass door into the office.
"There is nothing more terrifying than hearing multiple people get shot while you're under your desk and then hear the gunman reload," he tweeted.: