The day after police charged a man in the Atlanta University Center shooting that injured four students last month, investigators released additional surveillance footage of a second suspect in the case.

Authorities also announced that the reward for information in the shooting has been increased from $2,000 to $6,000 after contributions from two Atlanta City Council members.

In the footage released Thursday evening, several people can be seen fleeing the area in front of the AUC library moments after the shooting. One of those people, police said, is a man authorities believe exchanged gunfire with Isaiah Williams in front of a crowd of about 200.

Williams, 21, turned himself in to police Wednesday. He is charged with aggravated assault, aggravated battery, possession of a firearm during the commission of a felony and criminal attempt to commit murder, Atlanta police spokesman Carlos Campos said.

RELATED: 21-year-old charged in Atlanta University Center shooting

Authorities said Williams is not enrolled at any of the AUC institutions.

The shooting occurred Aug. 20, just hours before the start of the new school year, AJC.com previously reported. The students were attending a block party in front of the library when shots rang out about 10:30 p.m.

The victims — two Spelman College students and two Clark Atlanta University students — were taken to a hospital with injuries ranging from graze wounds to gunshot wounds, according to Atlanta police.

“Initial investigation seems to indicate an argument broke out between two parties prior to the shooting,” Campos said at the time. “It appears the women were not the intended targets of the shooting.”

The injured students were later identified as Erin Ennis, 18, of Powder Springs; Maia Williams-McLaren, 18, of Boston; Elyse Spencer, 18, of Rochester, N.Y.; and Kia Thomas, 19, of Jonesboro.

MORE: How fun flashed into fear: AUC shooting victim recalls night of terror

Williams waived his first appearance hearing Thursday morning, but his attorney, Bruce Harvey, told Channel 2 Action News his client should have been given a bond.

“This is a young man that’s never, ever been in trouble before,” he told the news station. “... We’re here to contest these charges.”

Police are asking anyone who recognizes the suspect or any of the potential witnesses seen in the video to come forward. The cash reward in the case, Campos said, is three times larger than usual thanks to financial contributions from council members Cleta Winslow and Amir Farokhi.

The increased reward must be approved by the rest of the City Council members first, police said.

Winslow, whose district includes the AUC campus, said she is relieved an arrest has been made.

“Hopefully, he will reflect on the brutality and senselessness of the shooting incident on August 20th that could have easily led to the loss of life for many of the innocent bystanders,” she said in a statement.

Anyone who recognizes the outstanding suspect or any of the students in the latest video is asked to contact CrimeStoppers at 404-577-8477 or online at www.StopCrimeATL.com.

In other news: 

The man wore a mask and had a handgun with red laser sights during his crimes.