RICHMOND, Va. (WRIC) — Seven people were shot, two fatally, when gunfire rang out Tuesday outside a downtown theater in Richmond, Virginia, where a high school graduation ceremony had just ended, causing hundreds of attendees to flee in panic, weep and clutch their children, authorities and witnesses said.

The two people killed in the shooting were 18-year-old Shawn Jackson and his father, 36-year-old Renzo Smith, according to a family representative.

A 19-year-old suspect tried to escape on foot but was arrested and will be charged with two counts of second-degree murder, Interim Richmond Police Chief Rick Edwards said during a nighttime news conference, during which he confirmed the two fatalities.

Five others were wounded by the gunfire outside the state capital’s city-owned Altria Theater, which is across the street from a large, grassy park and in the middle of the Virginia Commonwealth University campus. At least 12 others were injured or treated for anxiety due to the mayhem, according to police.

“As they heard the gunfire, it was obviously chaos,” Edwards said. “We had hundreds of people in Monroe Park, so people scattered. It was very chaotic at the scene.”

Edwards said there were officers inside the Altria Theater when they heard gunfire from outside the building around 5:15 p.m. A witness told Nexstar’s WRIC they heard dozens of shots fired.

Four firearms were recovered at the scene, sources told WRIC.

Video captured by someone at the graduation shows the moments that gunshots were heard and a brief few seconds of the panic that ensued.

Police initially said two suspects were detained, but Edwards said later that they determined one of them was not involved.

Richmond Mayor Levar Stoney vowed to ensure anyone responsible faces justice.

“This should not be happening anywhere,” Stoney said.

Two people were treated for falls; one juvenile was struck by a car and sustained injuries that were not life-threatening; and nine people were treated at the scene for minor injuries or anxiety, according to police spokeswoman Tracy Walker.

Richmond Public Schools Superintendent Jason Kamras said the new graduates were outside taking photos with families and friends when the shooting broke out.

“I don’t have any more words on this,” Kamras said. “I’m just tired of seeing people get shot, our kids get shot. And I beg of the entire community to stop, to just stop.”

As he heard the gunshots and then sirens, neighbor John Willard, 69, stepped onto the balcony of his 18th-floor apartment. Below, he saw students fleeing in their graduation outfits and parents hugging children.

“There was one poor woman in front of the apartment block next to ours who was wailing and crying,” Willard said, adding that the scene left him deeply saddened.

Edythe Payne was helping her daughter sell flowers outside the theater to students as they left the ceremony. She told the Richmond Times-Dispatch that the shooting caused a panic on nearby Main Street, which was packed with people at the time.

“I felt bad because some elderly people were at the graduation and they got knocked down to the ground,” Payne said.

The school district said a different graduation scheduled for later Tuesday had been canceled “out of an abundance of caution” and schools would be closed Wednesday.

The mass shooting, the latest in a nation increasingly accustomed to them, prompted calls for reform.

“The gun violence epidemic is a public health crisis that we must address,” U.S. Rep. Jennifer McClellan, a Democrat whose district includes Richmond, said in a statement. “We cannot continue to live in fear. We must address the root causes of gun violence and pass common sense gun safety policies that protect our communities.”

Republican Lt. Gov. Winsome Earle-Sears, an ardent gun-rights advocate, said in remarks to news outlets near the scene that the problem lies not with guns but with criminals.

“We have to figure out what’s going on in our communities,” she said.

The Associated Press contributed to this report.