Almost 4000 homicides took place in New York City between 2003 and 2011. They were not uniformly distributed. The base map shows sensus blocks with % black population as the variable being colored.
The dots are controlled by the slider bar at the top. Each time the slider stops, the map is updated with a new SQL query showing just the homicides that took place in census blocks wiht more than the indicated % of white population, and the total number of homicides is updated to reflect the threshold %.