Five people were killed in a shooting inside the newsroom at the Capital Gazette newspaper office in Annapolis, Maryland, one of America's oldest newspapers.
Here's what we know so far about Thursday's attack, which also left two wounded:
The victims
The five victims were employees of the Capital Gazette, authorities said:
-- Wendi Winters
-- Rebecca Smith
-- Robert Hiaasen
-- Gerald Fischman
-- John McNamara
Hiaasen, 59, an editor and columnist, was the first victim publicly identified The brother of best-selling author and journalist Carl Hiaasen, he was a feature writer at the Baltimore Sun for 15 years before moving to the Gazette in 2010 as an assistant editor.
Two people with minor injuries were taken to Anne Arundel Medical Center in Annapolis. They did not suffer gunshot wounds, and one was released from the hospital, spokesperson Loren Farquahr said. The other patient was expected to be released late Thursday.
A third person was transported to the University of Maryland Medical Center in Baltimore. No information was provided on the victim's condition or injuries.
The suspect
Multiple law enforcement sources identified the suspect as Jarrod Warren Ramos, a man in his 30s. Police are searching an address associated with his name, law enforcement officials tell CNN. He was found hiding under a desk in the building, Anne Arundel County Executive Steven Schuh said.
The suspect had no identification when he was apprehended and the FBI found no information about him immediately in the system, a law enforcement source said. His fingerprints appear to have been altered, making it difficult to identify him, two law enforcement sources said. He was identified using facial recognition software, according to one law enforcement source.
Ramos has a connection to the paper, the sources said. He filed a defamation claim in 2012 against the paper but the case was dismissed.
They believe the suspect had some interaction with an executive at the newspaper previously, one of the sources said. The source cautioned that this is preliminary information, and the investigation is just beginning.
The motive
The shooting was a targeted attack on the newspaper that was intended to cause harm, said Anne Arundel County Acting Chief William Krampf.
Threats of violence were made over social media to the newspaper, some as recently as Thursday, he said.
What we don't know: Why, exactly, the newspaper was targeted, or who sent the threats.
The weapon
A long gun was used in the shooting, officials said, indicating it may have been a shotgun.
What we don't know: Was the long gun the only weapon the suspect allegedly intended to use? And what's the significance of a bag that was found outside the building containing multiple gas cans?
