A memorial was set up at the location in Alexandria where Julian Dawkins was shot and killed. (John McDonnell/THE WASHINGTON POST)

An Arlington deputy sheriff was arrested and charged with murder Thursday by Alexandria police in the shooting death of a 22-year-old man last week.

Police arrested Craig Patterson, 44, at a Spotsylvania County home Thursday evening, Alexandria police officials said on their Web site just before 11 p.m.

Julian Dawkins, a shuttle driver for “PBS NewsHour,” was found shot just before 1 a.m. on May 22 on Lynhaven Drive in Alexandria. Police soon identified Patterson, who was off-duty at the time, as the shooter, but the case has been shrouded in secrecy.

On Tuesday, about two dozen supporters of Dawkins’ gathered outside the Alexandria courthouse to express their concern that no charges had been filed in the case.

Family members have said that Dawkins was on Lynhaven Drive on the night of the shooting to celebrate his cousin making the Washington Mystics roster.

Just what happened that night between Dawkins and Patterson has not been made public. Officials did not release any details about the arrest warrant Thursday night or further information about their investigation.

Dawkins was a T.C. Williams High School graduate who had worked at PBS since June 2010, family members said.

Patterson is a 17-year veteran of the Arlington County department. Last week, he was placed on paid administrative leave during the investigation.

RELATED: PBS’s Gwen Ifill’s eulogy of Dawkins