I do not for a moment believe that its main impetus is the desire to save lives however.
Notice the tricky little dance in the text, whereby they point to the high rate of gun ownership in Texas as a reason why a city needs a sonic surveillance network to locate gun shots. This kind of lie (we call it “fake news” now, but it’s just a form of lie – we could call it “the subtle art of the lie”) will always sway a few people and so it will continue to be used.
In reality of course, the city and state governments which commit the most significant infringements against the right to bear arms will tend to have the higher rates of violent crime in those areas as a result. They know this, and yet call for more of the cause, presenting it to us as the cure.