Authorities said U.S. Marshals spotted the 26-year-old fugitive riding a bike down the street in the 400 block of LaVenture Road at about 2:40 p.m.
When the fugitive saw the federal officers, he pulled out a gun and opened fire at them. U.S. Marshals returned fire, killing the suspect.
No one else was injured.
Mount Vernon police have taken over the investigation into the shooting. The fugitive reportedly was wanted on a second-degree assault warrant.
Aerial footage shot by KOMO's Air 4 shows a body in the street covered by a sheet.
Investigators also have marked the positions of numerous shell casings on the pavement.
This is a developing news story. More information will be posted as it becomes available.