Police said the gun that was used is described as a long gun," meaning a rifle or a shotgun."
Annapolis, United States: The person suspected of killing at least five people at a newspaper in the US state of Maryland is a white adult male, a police spokesman said.
The suspect, who is in custody, is "a white male, adult male, and the gun that was used is described as a long gun," meaning a rifle or a shotgun, Lieutenant Ryan Frashure told journalists.
It is estimated that three people were wounded in the shooting, Frashure said.
The shooting took place inside the offices of the Capital Gazette, a newspaper in the historic city of Annapolis, an hour east of Washington.
A reporter for the daily, Phil Davis, tweeted that a "gunman shot through the glass door to the office and opened fire on multiple employees."
Mass shootings are a common occurrence in the United States.
While advocates of tougher gun laws have stepped up their efforts in the wake of school shootings this year, including the killing of 17 people at a Parkland, Florida high school in February and the killing of 10 people at a Texas high school in May, the results have been relatively modest so far.