A new study by Professor Franklin Zimring of the University of California, Berkeley, School of Law provides an in-depth analysis of the factors that influenced the dramatic twenty-year decline of street crime in New York City. According to the study, which was recently discussed in Scientific American, the rate of common crimes such as homicide, robbery and burglary dropped by more than 80 percent in New York City. By 2009, the homicide rate was lower than it was in 1961. Zimring suggests that one of the most influential factors in the reduction of crime rates was the improvement of policing around the city. Beginning in 1990, New York City added over 7,000 new uniformed officers. Along with adding new police to the streets, the city implemented several new strategies that were focused on high-crime settings. One of the tactics was deploying more police officers in crime "hotspots" that were determined by sophisticated data-mapping technology. Zimring concludes, "The steady, significant and cumulatively overwhelming crime decline in New York is proof that cities as we know them need not be incubators of robbery, rape and mayhem." The article also dispels some of the misconceptions about the drop in crime: Zimring states that it was not due to changes in the ethnic makeup of the city, to shifts in illicit drug use, or to an increased use of incarceration.