By default, GTA SA has a unique police officer model for each city. However, there is only one police biker for the entire state. He's a bit of a nonsense, as his model name seems to indicate that he's an LS biker. In addition, Rockstar left in gta3.img two full use models for SF and LV bikers. Why not make them usable? This mod (or rather this plugin) adds them to the city as they should be placed according to their names. Believe me or not, mods don't spawn cops by themselves, just exe procedure hacks. However, you don't even have to believe me as an open source mod. Put cbo.cs in GTA San Andreas CLEO directory and peds.ide in GTA San Andreas data directory to install the mod.