A gunman sprayed bullets from a moving vehicle into a crowd in southeastern Washington, killing four and wounding at least five others, before leading police on a chase into a neighboring county.
Three people were arrested in the drive-by shooting Tuesday, but investigators said the motive wasn't clear.
Six men and three women were hit by the gunfire around 7:30 p.m., said D.C. Police Department spokesman Officer Hugh Carew. Fire Department spokesman Pete Piringer says all were in their 20s and 30s, except for one teenager.
By late Tuesday, one victim had died at the scene, a second was pronounced dead at the hospital and the third died in the operating room, hospital officials said. Early the next day, police spokeswoman Gwendolyn Crump said the fourth victim had died.
Four D.C. officers were slightly injured while chasing a suspect's vehicle into neighboring Prince George's County in Maryland, authorities said. A weapon was also recovered.
The Washington Post reported that police pursued a van from the scene, aided by a helicopter.
The shootings were in a neighborhood near a water treatment plant and Bolling Air Force Base. Sections of southeastern D.C. have problems with crime, but residents told local media they were surprised by the violence and didn't consider the neighborhood dangerous.
However, D.C. Councilman Phil Mendelson said that the area where the shooting happened is known for drugs and related violence.
"It's not a stranger to violent activity, unfortunately," said Mendelson, the chairman of the D.C. Council's Committee on Public Safety and the Judiciary.
Mendelson said he didn't have further details on the investigation.
Washington reported 143 homicides last year, the fewest in nearly 50 years.