Wesley Brownlee was arraigned in a Stockton courtroom in the serial gun slayings that shook this city days after a weekend arrest that authorities say may have stopped another killing. Brownlee, 43, sat and listened to the charges read by San Joaquin Superior Court Judge John Soldati, in a courtroom crowded with reporters and victims’ families for a case that set Stockton on edge and garnered national headlines. In San Joaquin Superior Court, Brownlee was charged with three counts of murder for the deaths of Jonathan Hernandez Rodriguez, 21, who died Aug. 30; Juan Cruz, 52, who died Sept. 21; …