"It's important for you to know that being a thorough investigation, it could take time, even weeks," Secretary Brian Moran told students at UVA. "We ask for your patience."
The incident early Wednesday
involved uniformed alcohol control agents and Martese Johnson, an African-American student at UVA. It made headlines around the country and prompted Gov. Terry McAuliffe to order an independent Virginia State Police investigation into what happened.
Video from the incident shows Johnson pinned to the ground, screaming: "I go to UVA! ... You f****** racists! What the f***? How did this happen?" An officer can be heard telling the man to stop fighting.
He needed 10 stitches to close the gash in his head, Watkins said.
A source close to Johnson's family told CNN's Don Lemon on Friday that Johnson was taken to the UVA health center over concerns about head swelling. The source says he was taken only as a precaution.
Johnson was charged with public intoxication and obstruction of justice, according to the Virginia Department of Alcoholic Beverage Control, which acknowledged he suffered injuries during his arrest. The agents were placed on administrative duties during the investigation, the agency said.
An agency spokeswoman identified the arresting officer as "J. Miller" but did not provide names for other officers involved in the arrest.
The Black Student Alliance said the arrest reminds black UVA students "of the gruesome reality that we are not immune to injustice." In a news release, the university called the arrest disturbing, and University President Teresa Sullivan issued a statement saying that "every member of our community should feel safe from the threat of bodily harm and other forms of violence."
Johnson's arrest prompted protests among students demanding "Justice for Martese" after images circulated showing his bloodied face and clothing.
Friday's forum was held a theater on the UVA campus. Media were not allowed to ask questions or bring cameras into the forum. Student leaders had originally said the event would be live-streamed on the Internet, but it was not.
"This is a student space -- a chance for students to ask the questions they feel are most pressing to Virginia's most senior law enforcement officials," the group said on Facebook.
In a Facebook post, the university's Student Council said representatives from Charlottesville, Virginia, police, Albemarle County police and the state Alcohol Beverage Control were to attend the forum "to engage in a conversation about their relationship with students, or lack thereof, and about the issue of police brutality."
Charlottesville police Chief Timothy Longo said wounds still run deep from a history of racial inequality and division in the United States, but that change must come. He said there's "a long way to go."
"What happened this past week has shaken your trust," he said. "It's my responsibility to regain it."
Separately, Virginia Attorney General Mark Herring appealed for patience.
"Certainly the images that we've all been looking at in Charlottesville are shocking, but it's really important that we get the facts out and understand exactly what happened," Herring said.
Students leaders asked their contemporaries to tweet questions in advance. By Friday afternoon, only a handful of tweets had crossed using the hashtag "#policedialogue.
"Is the problematic influence of implicit bias discussed at all during police training," Twitter user yaejmeister asked.
Among other questions, one student asked why alcohol control agents have police powers.
A third wondered "is catering to UVa's hypersensitivity
preparing our students for the world outside of 'grounds'?"
The incident comes amid a continuing nationwide debate over the use of force by police, particularly involving African-Americans, following the deaths last summer of Michael Brown
in Ferguson, Missouri, and Eric Garner
in New York.
Grand juries in both communities declined to indict white police officers in the deaths, leading to angry protests nationwide and calls for renewed attention to claims of police bullying and brutality.