Five people were killed in a shooting inside the newsroom at the Capital Gazette, one of America's oldest newspapers, in Annapolis, Maryland.
Here's what we know so far about Thursday's attack, which also sent three other people to hospitals:
The five victims were employees of the Capital Gazette, authorities said:
• Wendi Winters, special publications editor
• Rebecca Smith, sales assistant
• Robert Hiaasen, assistant editor
• Gerald Fischman, editorial page editor
• John McNamara, staff writer
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, spokeswoman Loren Farquhar 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.
Jarrod Warren Ramos has been charged with five counts of first-degree murder, according to court records.
Police are searching an address associated with his name, law enforcement officials told CNN. He was found hiding under a desk in the building, Anne Arundel County Executive Steven Schuh said.
Ramos, 38, was scheduled to have a bail hearing Friday in Annapolis.
The shooter 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 he had some interaction with an executive at the newspaper previously, one of the sources said. The source cautioned that this information is preliminary, and the investigation is just beginning.
The shooting was a targeted attack on the newspaper, said William Krampf, acting chief of the Anne Arundel County police.
Threats of violence were made over social media to the newspaper, some as recently as Thursday, he said.
What we don't know: Was the gunman targeting anyone in particular or just the newspaper?
"This person was prepared to shoot people. His intent was to cause harm," Krampf said.
Krampf did not say who was behind the recent threats.
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 found outside the building containing multiple gas cans?
Correction: A previous version of this story incorrectly spelled the name of Loren Farquhar.