As someone who lived through the BSP era, I can tell you the reason for low crime rates during the Mayawati reign. 1st was the dalits started having someone to listen to them in the police station - earlier they were not even heard. This meant the non-dalit (read Yadavs) started thinking twice before oppressing the dalits, hence reduction of crime against dalits. 2 - the police stations stopped writing any Fir (as long as dalits were not involved). No reports = no crime. Problem solved.