An interesting service known as shotspotter can not only differentiate between gunshots and pyrotechnics, the service has also managed to map out the location of all (most) gunshots in the D.C area since 2009, painting an interesting picture that easily identifies areas of the city where you might want to be careful, particularly if you aren’t packing in order to protect yourself!
Some details, according to an article in the Washington Post – The District’s ShotSpotter has detected 39,000 outdoor gunshot incidents in the past eight years. Sensors cover about a third of the city and are concentrated where gun crime is highest. It allows police to respond immediately to the exact location where shots are fired and provides a dramatic picture of the danger faced in many neighborhoods.
It should be noted that the system does have some difficulties when interference from persons, tall buildings, or alleys get in the way of soundings.