It would be the same issue if he simply assaulted them with his fists -- the recording would help to determine if he was being threatened. You can look up the

It would be the same issue if he simply assaulted them with his fists -- the recording would help to determine if he was being threatened. You can look up the case on Wikipedia and elsewhere if you're curious: https://en.wikipedia.org/wiki/1984_New_York_City_Subway_shooting#Incident https://en.wikipedia.org/wiki/1984_New_York_City_Subway_shoo... Bottom line, it's really not hard to imagine that audio recording would help determine important facts of a case; this shouldn't be controversial in and of itself. The issue is the relative cost to personal liberty.