Question - identifying shooters

A while back it was announced that the 71st Precinct was going to be one of a handful of precincts in NYC that would be testing out he latest in identifying shooters.  The technology allows devices to be placed on buildings in the neighborhood and when a gun is fired they can red soundwaves and pinpoint the location where the gun was fired within 60 seconds.  I believe DNA Info ran a story on this a few months back as well.  Was there a discussion on here about this?  Anyone have the link the to eh DNA Info article?  It is supposed to start next month.