DALLAS (CBSDFW.COM) – It was a little more than 24 hours ago when Brian Clyde parked his car in downtown Dallas and walked up to the Earle Cabell Federal Building in full tactical gear. He randomly fired shots, pointing his rifle inside and outside the building.

Federal officers eventually returned gunfire and wounded Clyde. He was taken to Baylor University Medical Center where he was pronounced dead.

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Dallas Police tend to the federal building shooter after he was shot by police (credit: George Rebecca)

As the FBI continues the investigation into the shooting, the Earle Cabell Federal Building is closed for business and to the public. Employees, however, were expected to report to work.

On Tuesday FBI agents were busy snapping pictures of the shooting aftermath as employees made their way inside the building.

Now more than a day later, investigators still have questions as to the 22-year-old’s motive. Clyde left a trail of Facebook posts that could give authorities insight. In the posts, the gunman brandished ammunition and weapons as he spoke of “a storm” coming.

Seeing the video and images of the shooting on June 17 bring back feelings of terror for Michael Mata. “It’s still a lot of fear, fear because you know we buried five officers three years ago in a similar incident,” he said.

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The Dallas Police Association president told CBS 11 News that while officers can’t train for every scenario, they can be prepared. “It was imperative that those officers engage him quickly and effectively — which they did,” he said. “You never know when this is gonna happen and once again here we are. We’re on national news showing another gunman out here trying to take civilian lives.”

At a press conference Monday, U.S. Attorney Erin Nealy Cox praised law enforcement for their swift response. “These guys are our hero’s today we owe them a debt of gratitude,” she said.

Dallas resident Tim Brown had a birds eye view of the shooting from his 8th floor apartment. He saw a masked man, now known to be Clyde, approach the federal courthouse with a rifle in his hand. “He definitely had this planned out,” Brown said. “He had a vest on, it looked like CAMO pants on and he had boots on.”

Brian Isaack Clyde (courtesy: Facebook)

CBS 11 has learned that Clyde spent time in the U.S. Army but was discharged after less than two years. Army officials aren’t commenting on why he was discharged.

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The FBI is looking for more information about Clyde and the shooting. They have issued an open request for pictures, video and information from witnesses and his acquaintances. Those who have something to contribute to the investigation should contact officials at 800-CALL-FBI or click here to submit information, video and tips online.