How about ultra-low power microprocessors coupled with capacitors, solar cells, and MEMS microphones, that can use a continual Fourier analysis to identify guns

How about ultra-low power microprocessors coupled with capacitors, solar cells, and MEMS microphones, that can use a continual Fourier analysis to identify gunshots? The internal memory could be kept so small, as to preclude the possibility of recording someone's voice for longer than one phoneme. These could then be sprinkled around someplace like the gang territory parts of Oakland. EDIT: Seems that another commenter is aware of a company doing something like this: http://www.shotspotter.com/company http://www.shotspotter.com/company