Maryland's Capital Gazette Newspaper Shooting Suspect Identified as Jarrod Ramos

Jarrod Warren Ramos was identified as the gunman in the shooting at the Capital Gazette newsroom in Annapolis, Maryland Thursday, law enforcement sources told CBS News.

The 38-year-old Ramos allegedly opened fire in the newsroom, where five people were shot and killed.

According to CBS News' law enforcement sources, he allegedly used a shotgun. When he was arrested, he was carrying smoke grenades or flash-bang grenades, police said.

Police identified the victims as Wendy Winters, Rebecca Smith, Robert Hiaasen, Gerald Fishman and John McNamara, all of whom worked for the newspaper.

During a press conference, Anne Arundel County acting police chief Bill Krampf called the shooting a "targeted attack," adding, "This person was prepared to shoot people. His intent was to cause harm."

Ramos was uncooperative when taken into custody. He was not carrying identification and reportedly damaged his finger tips to avoid being identified by authorities, CBS News sources said. Police and investigators had to use facial recognition software to compare his face to diver's license photos to identify him.

A Twitter account that appears to belong to Ramos includes messages about a long-running legal case between Ramos and the Capital Gazette.

According to CBS News, Ramos pleaded guilty to criminal harassment in 2011 and the details appeared in a 2015 Maryland Court of Special Appeals opinion. An article about the case appeared in one of the Capital Gazette's papers. In 2012, he filed a defamation lawsuit against the paper, which was later dismissed.

Ramos used a photo of Eric Hartley, the columnist he sued in his defamation lawsuit, as his profile picture on Twitter, reports the Baltimore Sun. He did not use the Twitter page for more than two years until just minutes before the shooting. "F– you, leave me alone," the tweet reads.

The shooting happened before 3 p.m. ET. Crime reporter Phil Davis described the scene as "like a war zone" in an interview with the Baltimore Sun, which owns the Gazette.

"I'm a police reporter. I write about this stuff — not necessarily to this extent, but shootings and death — all the time. 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," Davis told the Sun.

"Prior to departing Wisconsin, I was briefed on the shooting at Capital Gazette in Annapolis, Maryland," President Donald Trump said in a Twitter statement. "My thoughts and prayers are with the victims and their families. Thank you to all of the First Responders who are currently on the scene."