The shooting happened about 8:30 p.m. Saturday on the 1400 block of South Downey Avenue near the border with the city of Commerce.
The two deputies involved said it all began when they saw two men walking. They said one of the suspects was carrying a pistol.
The deputies ordered the suspects to show their hands, and during the confrontation, the deputies shot the man carrying the gun twice.
He was taken to the hospital in critical condition. The second suspect was arrested.
The incident remains under investigation.