On Sunday, a local man fired his gun four times at his brother, and police say that the ShotSpotter picked up the gunshots and sent alerts to officers nearby.
The alerts came to DPD before anyone called 911, and police arrived at the scene two minutes before someone talked to a dispatcher about the gunshots.
Because the ShotSpotter picked up the location of where the shots rang out, police could see the gunman running from the scene and helped the victim as soon as possible.
ShotSpotter is being used in two police precincts, and Detroit police want a $7 million expansion of the program.
There is controversy over the ShotSpotters; some believe that the sensitive sensors are an invasion of privacy, even though the sensors are engineered to be triggered only by gunshots.
Below is a video of how ShotSpotters work: