TULSA, Oklahoma - A gunman opened fire on the plaza on the north side of the Tulsa County Courthouse Wednesday afternoon.

News On 6 crime reporter Lori Fullbright identified the suspect as Andrew Joseph Dennehy, 23, of Tulsa.

Tulsa County Sheriff's deputies say Dennehy walked onto the plaza and started shooting a pistol into the air.  Deputies on duty at the courthouse confronted the man and shot him.

An employee of the library on the north side of the plaza took a series of photos of the incident.

One deputy was shot in the hand, another bystander was hit and went to the library for shelter.  Deputies say it's not clear yet if the bystander was hit by a bullet fired by the gunman or other deputies.

A veteran Tulsa County bailiff says it was panic on the plaza.

"We heard three loud pops, and we looked out our window here to the east and we could see people looking at the plaza," said Jean McGuire, courthouse bailiff.

"So we go to the north side windows, and I could see the white male standing there. In a split second, 2 or 3 more shots. I just saw him fall and the gun was at his feet."

EMSA says an adult male was treated on the scene and transported in critical condition. Another adult male was transported to the hospital in serious condition.

Two other victims, one male and one female, received minor injuries; one was transported to the hospital in fair condition and the other refused transport, according to EMSA. 

Start the slideshow

With the courthouse locked down, investigators searched for shell casings and checked out Dennehy's vehicle for more clues. Onlookers stayed hours after the shooting, shocked at what they'd seen.

"There's a lot of innocent people right here for people to be walking around with guns here... that's kind of crazy, scary," said Miguel Rosales, witness.

A Tulsa police officer escaped serious injury when her squad car rolled over while she was responding to the shooting scene.

News On 6 confirmed that Dennehy's brother - Brian - was shot and killed by Tulsa Police in 2005.

Tulsa Police believed Brian Dennehy had beaten his own grandfather to death.

When officers tracked him down to a Tulsa apartment complex, he opened fire on police, hitting a squad car. The officer in that car returned fire, killing Dennehy.

The Tulsa County courthouse will open for normal business operations with all entrances accessible on Thursday March 8, 2012.