Authorities say the officers were on bicycles when the truck swerved around a bus, striking them at 9 p.m.
A traffic aide and two pedestrians were also hit for a total of five victims.
One officer is listed in very critical condition. The others have non-life-threatening injuries.
D.C. Metro Police Chief Peter Newsham said a weapon was recovered from the suspect's vehicle.
When asked if he could rule out terrorism, Newsham replied, "We have to look at that very closely. We do not have a motive at this time."
Both the driver and another person in the vehicle were arrested.
Police spokeswoman Aquita Brown said in an email Friday that 22-year-old Brandon Figures-Mormon of Disputanta, Virginia, and his passenger, 23-year-old Dwayne Taylor of Prince George, Virginia, also face weapons charges.