Nineteen people were arrested during a DUI checkpoint in Riverside, authorities announced Saturday. The checkpoint was conducted near the intersection of Market and Fifth Streets from 8 p.m. Friday to 2 a.m. Saturday, according to the Riverside Police Department. A total of 626 vehicles were contacted, resulting in the arrest of 14 people suspected of operating a vehicle unlicensed or with a suspended or revoked license. Three others were arrest…