The shooting was reported around 5:35 p.m. in the area of Box Springs Boulevard and Eastridge Avenue, near the 215 Freeway.
Riverside police say a CHP officer conducted a traffic stop and the suspect produced an assault rifle and began firing. Officers fired back.
The suspect was struck at the scene and officials later said the individual had died.
"One of our officers succumbed to the injuries sustained," the CHP tweeted.
Two other officers were also injured at the scene, but the extent of their wounds was not immediately available. Other law enforcement agencies, including Riverside police and the county sheriff's office rushed to the scene to assist after the officer needs help call went out.
One bystander was also injured, but it is believed the person was struck by debris or shrapnel, not gunfire.
At least two CHP vehicles had visible gunshot damage in the rear windshields at the scene.
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