I've written a couple of articles about defending yourself in an environment where the justice system is weaponized against you:
In the first of those articles, dealing with politically-correct investigations and/or prosecutions, I noted:
What about cameras mounted on light poles or buildings to cover the street? Many big cities now have thousands of them in law-enforcement-monitored networks, as well as gunfire location systems to detect when and where firearms are used, and send responding officers straight there. If you use a firearm to defend yourself, you may be recorded on video and audio by such systems, providing evidence that may be used to identify, arrest and convict you. Therefore, if you might have to take such action, you'll need to take that into account - particularly by avoiding areas where those are major concerns, or remaining as concealed as possible, or making yourself hard to recognize, while doing what's necessary and exiting the area.
Those gunfire location systems have been problematic in the past, but their technology has been steadily improved. It's now good enough to produce meaningful results on the battlefield, and that will undoubtedly filter down to urban policing in the not too distant future. Strategy Page reports:
Israel recently introduced Othello-P, a new GDS (gunfire detection system) that can be vehicle-mounted or used from a stationary position on the ground. Othello-P uses acoustic and infrared optical acoustic sensors along with new software to instantly locate where the gunfire or an RPG (rocket propelled grenade) is coming from. One Othello-P system provides 180-degree surveillance while two Othello-Ps provide complete (360-degree) surveillance. Othello-P detects the flash, blast and shock wave of a projectile day or night no matter where the shooter is, including higher elevations or even from aircraft. Rifle fire can be detected up to 400 meters distant while RPG rockets can be detected up to 2,000 meters away. Not only are nearby troops instantly alerted, via the new Israeli battlefield communication network, but also headquarters for operations in the area who can quickly call in air or artillery strikes. Othello-P can also be mounted on unmanned vehicles, which Israel had been using for over a decade and current models can be used in urban or open terrain. These vehicles already use visual and audible sensors to detect threats.
Gunfire detection systems have been around for over three decades. The first practical system was developed because a French scientist applied techniques used by ships and submarines to detect submarines to gunshot detection systems. Details of this breakthrough spread through the scientific community and in 1992 a California based seismologist (earthquake detection specialist) working for the United States Geological Survey developed a gunshot detection system he believed could accurately detect the location of gunfire in urban areas. He did this as a public service because nearby Menlo Park had a major problem with gun crime and the police were looking for a practical solution to detecting the location of such incidents quickly. The proposed system was installed, tested and it worked. These systems have gotten cheaper and more effective since then and are widely used in cities with a lot of illegal gun use. Police were able to show up at the scene of gunfire quickly and that, combined with growing use of surveillance cameras, reduced gunfire incidents by identifying and prosecuting many of the shooters. There is still illegal use of firearms, but a lot less of it compared to cities without the gunfire detection systems.
As Israel recently demonstrated, the greatest advances in gunfire detection technology have come from the military. One of the first, and most useful, of these military gunfire detection systems was developed in a few months in 2004, in response to a U.S. Department of Defense request for an affordable acoustic sniper detector. Testing delayed it from entering service immediately but by 2005, the system was being used in Iraq. This is another example of how wartime urgency speeds the development of new technology.
Acoustic gunfire (sniper) detectors have been in the field for two decades and have gotten better each year.
There's more at the link.
In general, I support these systems as a worthwhile technology that can help make our cities safer. Unfortunately, when leftist politically-correct District Attorneys seek to prosecute those who defend themselves rather than their attackers, who misuse the criminal justice system to persecute law-abiding citizens, and whose decisions are motivated by politics rather than the law . . . such systems can become an instrument of persecution and oppression instead.
If you are forced to defend yourself and/or your family in a "blue city", be aware that this technology may be used against you, and will bring police response more swiftly and more accurately than you might think. Staying out of trouble becomes a major priority, in order to avoid such complications: and if you have no choice but to act in self-defense, and know you're going to face an official witch-hunt because of the color of your skin or other politicized factors . . . conduct yourself accordingly. Be aware of the threat(s), and take them into account in your actions.