First of all, I doubt many New Yorkers would know what you're talking about if you shouted, "Zero tolerance doesn't work." There was no magic bullet in 1995 that caused crime to decline. Crime began to decline years earlier, and was the result of many factors, including more aggressive (and enlightened) policing. NYPD commissioner Lee Brown (1990-1992) introduced the concept of community policing, and crime in NYC began to decline. His successor, Raymond Kelly (1992-1994) continued the policy, and introduced zero tolerance, although it wasn't called that - it dealt with nuisance and quality-of-life crimes, such as pissing anywhere you wanted, subway turnstile jumping, squeegee men (the poster child), etc. The policy was an attempt to reverse the increasing perception during the 1970s and 80s that the city was out of control and ungovernable. It worked with community policing in getting communities more involved in crime prevention. Giuliani defeated Dinkins in the 1994 mayoral election, a nasty campaign. He replaced Kelly with Bill Bratton (1994-1996). Because of the political polarization that resulted from the election, Giuliani (a former prosecutor) began to downplay the decline in crime during the early 90s. Bratton introduced CompStat. He decentralized police decision making to the precinct level. The police force was increased by several thousand, and the Transit and Housing Police, until then separate entities, were merged into the NYPD. From a policing standpoint, I think these factors had more impact than a vague term such as zero-tolerance.