Riverside County District Attorney's Office | 4,020 followers on LinkedIn. The Riverside County District Attorney's Office, as the chief prosecutorial agency in the county, represents the People of the State of California in all criminal matters arising in Riverside County. The DA's Office, comprised of about 700 attorneys and support staff, serves the estimated 2.2 million residents across the vast 7,200 square miles that make up Riverside County -- the 10th largest county in the United States. We file, on average, more than 50,000 criminal cases each year and we are one of the largest DA's offices in the state.