Fairfield Police say the shootings occurred when federal investigators initially tracked down 27-year-old Markell Davis of Fairfield behind a Walmart Thursday afternoon. An agent shot Davis who was carrying a handgun.
Officers did not say if the suspect shot at the investigators.
Police on the scene then located Davis' older brother, 33-year-old Cory Davis of Suisun City, about 30 minutes later. Officers shot Cory Davis, who also was carrying a gun.
The brothers were taken to a local hospital. Their conditions are not known.
No officers were injured in the shootings.
The suspects were being sought in connection for their roles in two separate shootings in Fairfield and in Vacaville in February.