Amateurs
Law enforcement has been dropping the ball on basic investigative techniques for years. I'm not against the use of technology, but it's just a tool and the outputs of those tools need to make sense rather than the police slavishly believing the outputs even when they make no sense. Gunshot detectors can be a good tool if there are lots of gun crimes in an area. If a call comes in from somebody that there's been a shooting, the detectors can help narrow down where to look and possibly find where the shooting happened.
Gratuitous use of license plate readers can be an issue as it's often just mass surveillance. I know of a couple shopping centers that have them and the Los Angeles Police Department keeps extensive databases on number plates with patrol cars feeding in data 24/7. I know an LAPD officer that was in a class where they allowed him to look up his own car (the system isn't available to all officers) and he commented on how scary it was to see a listing of everywhere his personal car had been logged. He did notice one mistake as he knew that at that date/time he was a considerable distance away on a trip with his wife in his car. Facial recognition is also prone to big mistakes. I don't see a problem for a shop to use it so they know if somebody they've had issues with before returns, but again, it's a tool and there could be errors. For the police to arrest somebody based solely on a facial recognition system tagging them can be a huge problem. Often enough, it shows up the shortcomings when the wrong person is detained and it's completely obvious they are not the droid(s) the police are looking for.