ANNAPOLIS, Md. — A gunman who opened fire in what police are calling a "targeted attack" at a newspaper office in Annapolis on Thursday, killing five people in one of the deadliest attacks on journalists in U.S. history, has been identified, multiple law enforcement sources confirm to CNN.
Jarrod Warren Ramos, a man in his 30s, who sources say resides in Laurel, Maryland, has been taken into custody.
Ramos' rampage at the Capital Gazette followed social media threats directed at the newspaper, police say. Authorities said the man entered the building and "looked for his victims." He threw smoke grenades and fired a shotgun at his victims, according to Anne Arundel County Acting Police Chief William Krampf.
"This person was prepared today to come in, this person was prepared to shoot people. His intent was to cause harm," Krampf said.
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.
The suspected gunman was found hiding under a desk in the building, Anne Arundel County Executive Steven Schuh told CNN.
The man initially refused to cooperate, a law enforcement source said told CNN. He had no identification when he was apprehended and FBI found no information immediately in the system, the source said.
'Like a war zone'
Schuh said authorities responded to the shooting in "60 seconds."
"They went immediately into that building without a moment's hesitation and demonstrated incredible courage," he said. "It could have been a lot worse."
An employee on lockdown in a nearby building said responding officers "were hustling." Authorities evacuated about 170 people from the building, which is also home to other businesses and doctors' offices, Frashure said.
Daria McMiller, who works as an administrative assistant in a building next to the Capital Gazette building, says she was very impressed with the police response.
McMiller says she and her co-workers didn't hear any shots but they heard authorities yelling and saw police, FBI, state troopers and SWAT swarming to the scene.
"Some of them were still in civilian clothes and they were pulling their vests on as they ran towards the building," she said.
Four of the dead were killed at the scene; a fifth person, who was shot in the upper body and arm, died at the University of Maryland Medical Center, Schuh said.
In an interview with the Baltimore Sun, Phil Davis, a reporter who covers courts and crime for the paper, said the newsroom "was like a war zone".
Davis tweeted that the gunman shot out the glass door to the office and fired into the newsroom, sending people scrambling for cover under desks.
"A single shooter shot multiple people at my office, some of whom are dead," he wrote.
Davis added: "There is nothing more terrifying than hearing multiple people get shot while you're under your desk and then hear the gunman reload."
"I'm a police reporter. I write about this stuff -- not necessarily to this extent, but shootings and death -- all the time," he said. "But as much as I'm going to try to articulate how traumatizing it is to be hiding under your desk, you don't know until you're there and you feel helpless."
'A newspaper we live with every day'
Susan O'Brien, a spokesperson for the city of Annapolis, said the publication "is a newspaper we live with every day."
"Our hearts are with the family," she told CNN.
Earlier, Hogan tweeted he was "absolutely devastated to learn of this tragedy in Annapolis."
"Devastating. My heart is with Capital Gazette and the people of Annapolis right now," Maryland Senator Ben Cardin tweeted.
Capital Gazette Communications publishes multiple newspapers, including the Capital and the Maryland Gazette.
The Capital is one of America's oldest newspapers, beginning life as the Evening Capital in 1884.
The company that publishes it started in 1727 with the Maryland Gazette. In 1767, Anne Catharine Green became the first female newspaper publisher in the country and the Maryland Gazette fought the stamp tax that started the American Revolution.
For many decades, there were two papers that served the region -- The Maryland Gazette, a weekly, and the Evening Capital, a daily.
In 1981, The Evening Capital became The Capital. And in 1994, the company that owned it launched one of the first newspaper websites in the US with CapitalOnline.com.
Today, The Capital serves Annapolis, Anne Arundel County and Kent Island. It has a daily readership of about 67,000 and a Sunday readership of 83,000, according to the Baltimore Sun Group, which owns it.
'We are putting out a damn paper tomorrow'
The Capital Gazette had been threatened on social media as recently as Thursday, Krampf said. He said authorities are trying to confirm what account the threats came from and who sent them.
He said the threats "indicated violence."
Threats against journalists have been on the rise recently. Press freedom groups have also reported an increase in physical assaults on reporters, particularly at campaign events and other political venues.
Gazette reporters said their staff is small, and they are determined not to let the shooting deter them from their doing their jobs. Despite the shooting, they still planned to publish a paper Thursday night.
Multiple newsroom staffers, plus reporters from The Baltimore Sun, are working on stories for Friday's edition.
"The Capital is not a big newsroom. There are about 20 news staffers, a few more advertising. We are close. We are family. I am devastated," tweeted Danielle Ohl, a reporter.
"I can tell you this: We are putting out a damn paper tomorrow," another reporter Chase Cook tweeted.