A gunman opened fire in several locations in a string of random shootings Wednesday, killing a Washington, D.C., Metro subway employee and injuring three others.
The DC Metro worker was fatally shot after trying to intervene when the gunman got into a confrontation with a woman on the subway platform at the Potomac Avenue station, according to police.
"His heroism has to be recognized here today," Ashan Benedict, the executive assistant chief of police for the Metropolitan Police Department, said at a press conference Wednesday morning.
The employee was identified by DC Metro as Robert Cunningham, 64, a mechanic in its power department.
"Metro is mourning the loss of a heroic employee, Robert Cunningham, who intervened on behalf of a customer today at Potomac Avenue Station and was a victim of senseless gun violence," the agency said in a statement. "In his remembrance, Metro has lowered its flags to half-staff during this time of grief."
Police said they believe the shooter may have been trying to rob the young woman.
Benedict said a second employee was able to deescalate the situation and stop the string of attacks. He suffered minor injuries by shrapnel from the shooting of the other employee, police said.
The shootings began at about 9 a.m. on a Metrobus, where the gunman allegedly shot someone in the leg. The individual shot in the leg ran off and has since been interviewed by police and was transferred to an area hospital.
The suspect then shot another person in the leg inside the nearby subway station. The person was attempting to purchase a metro card when an altercation occurred and they were shot. The suspect then took the individual over the turnstile before they broke free.
Both of those shooting victims are being treated for non-life-threatening injuries, police said.
"The fact that our citizens have to intervene with an armed gunman is disturbing to me," Benedict said.
Officers found the suspect on the Potomac Avenue Metro Station train platform and took him into custody, but police do not yet know the motive for the attacks. A weapon was recovered on the train tracks.
"We have a gun violence problem in America, and sometimes unfortunately that comes into Metro. But this is not a Metro-specific safety issue. It's an American gun violence issue. And I think that's becoming increasingly clear all over America day in and day out," said Randy Clarke, general manager and CEO for the Washington Metropolitan Area Transit Authority.
ABC News' Beatrice Peterson contributed to this report.