The man suspected of firing a gun into a crowd of counter-protestors at a white supremacist rally in Charlottesville, Virginia has been arrested, Charlottesville police confirmed.

The man, identified as Maryland resident Richard Wilson Preston, has been charged with discharging a firearm within 1,000 feet of a school – a felony punishable by up to 10 years in prison. He is being held at the Baltimore County Detention Centre, according to the Baltimore Sun.

Police believe Mr Preston is the man who was caught on video shooting at counter-protesters at the rally.

A video tweeted by the ACLU of Virginia shows a white-haired man descending the steps of Emancipation Park, where the rally was held. He passes by a group of counter-protestors, some of whom yell at the rally attendees to “go home". One counter-protestor appears to throw an object at them.

The man identified by police as Mr Preston turns to the crowd and draws his weapon, yelling, “Hey n*****!” Someone in the crowd warns others to get down.

The man lowers his weapon, then raises it again and appears to fire one shot into the crowd. As he walks away, someone in the crowd cries: “That was a gunshot!”

The video also shows Virginia State Police troopers standing about 50 feet away. The officers do not appear to react to the gunshot.

Virginia State Police spokeswoman Corinne Geller told CNN the officers did not witness the incident or hear the gunshot.

"Had any one of our troopers witnessed that incident, they would have immediately acted just as they did for the other four arrests made during the weekend," she said.

The ACLU told the Baltimore Sun they had discovered the footage while reviewing photos and videos from the rally. The group said it gave the video to the FBI on 17 August, and to local police several days later.

Mr Preston was arrested on 28 August – two days after the ACLU released the footage on Twitter. The tweet received more than 12,500 retweets.

Mr Preston, 52, has been identified in news reports as an imperial wizard of the Ku Klux Klan chapter in Maryland.

In 2013, a man who identified himself as Richard Preston attended a community meeting in Cecil County, Maryland, as part of an attempt by the group repair their image.

At the meeting, Mr Preston said that the KKK was not a hate group, and had been falsely labelled as such. He said that the group only wanted to take back their country, which they felt was on the wrong path. He promised to continue speaking out about the Klan at community meetings.

"We're going to do this all over America nonstop," Mr Preston said. "We're not going to stop. We need to save America."

Charlottesville police said two more people had been arrested in connection with the rally: Daniel Patrick Borden and Alex Michael Ramos. Both were charged with malicious wounding.

One prominent rally participant, Christopher Cantwell, was arrested earlier this month on charges of malicious bodily injury and illegal use of tear gas. He was denied bail last week.

James Alex Fields Jr, the man accused of hitting and killing a counter-protester with his car, remains in jail on charges including second-degree murder.