# Law Enforcement Vehicle Chase Quesiton **URL:** \ **Category:** Factual Questions\ **Created:** [March 31, 2019, 9:30pm UTC](https://boards.straightdope.com/t/law-enforcement-vehicle-chase-quesiton/831822 "2019-03-31T21:30:46Z")\ **Posts on this page:** 4\ **Page:** 4
**Author:** ![excavating\_for\_a\_mind](https://avatars.discourse-cdn.com/v4/letter/e/e8c25b/32.png) [@excavating\_for\_a\_mind](https://boards.straightdope.com/u/excavating_for_a_mind)\ **Post date:** [April 6, 2019, 1:23pm UTC](https://boards.straightdope.com/t/law-enforcement-vehicle-chase-quesiton/831822/61 "2019-04-06T13:23:54Z")
> [@msmith537](#): > > Would that even work? .22 rounds aren’t particularly powerful. I highly doubt one of those rifles we used in summer camp for target practice would crack an engine block or penetrate a radiator. > > [I was watching a YouTube video the other day](https://www.youtube.com/watch?v=3zd-hMXeMoA), and even an aimed shot with a .50 cal anti-material rifle against a stationary vehicle isn’t a guaranteed insta-kill. You don’t have to crack the engine block. All you have to do is penetrate about 0.010" of soft copper (or, more likely in today’s cars, aluminum) tubing. A full-tube leak in a radiator will drain enough of the coolant to prevent proper circulation in a matter of minutes. Once the circulation is stopped, the engine will overheat and either shut down or a component will fail reducing the power and, eventually causing the engine to fail. And, it doesn’t even have to be a .22 rifle, I just used that as an illustration. Just a little bit of research might come up with a air-powered device that would shoot projectiles that would be accurate and have enough momentum to break through whatever plastic and whatever else (ac coils, perhaps oil coolers) that may be mounted in front of the radiator. My point is that instead of chasing a vehicle around for hours, it could be disabled quickly. The spike strips do not always work as some tires are not vulnerable to them, and they also require the officers to get very close to the vehicle in order to deploy them. As this is NEVER done, although there are certainly situations where it could be done safely and effectively, suggests to me that there are (nearly) universal police department policies against it. I do find it odd that such universal policies (if they exist) can be effective but these same departments cannot figure out how to institute a policy not to shoot unarmed law-abiding citizens. ---
**Author:** ![SamuelA](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@SamuelA](https://boards.straightdope.com/u/SamuelA)\ **Post date:** [April 6, 2019, 1:33pm UTC](https://boards.straightdope.com/t/law-enforcement-vehicle-chase-quesiton/831822/62 "2019-04-06T13:33:24Z")
> [@Tired\_and\_Cranky](#): > > I doubt **pkbites** remembers every detail of the police shutdown technology perfectly but who cares. Nearly every car on the road has a transponder system that allows you to unlock the doors by clicking a button. Door unlocking is controlled by the body control module (of whatever your carmaker calls it), which in turn is piped into a bus system that runs through the car. It would be a pretty trivial matter to link the bus system to the engine control unit (these are generally already connected for other reasons) and piggyback the door unlock receivers to instead disable the car. I’d be stunned if, after paying to program the system, it cost more than pennies to install in cars because it’s just lines of code. Then, the police cars would need a system to broadcast shutdown codes to fleeing cars. I’m guessing this is hundreds rather than thousands per patrol car. It might be only a bit more than the cost of a key fob, so $80 wouldn’t surprise me. Then, you need a system to securely transmit the shutdown codes to police when they need them. Cops already have encrypted laptops in their cars, so this isn’t magical technology either. There would also be costs to operate, secure, and maintain the database of car shutdown codes (which should be unique for each car). It’s true that this system doesn’t require GPS, so maybe that part of pkbites’s story was a red herring but a GPS tracker sure could help the police find the car they need to stop sooner. For what it’s worth, OnStar already has a system that works like this in car’s today, although it relies on a cellular connection rather than the door lock function. It also uses GPS receivers and the cell phone connection to report where the car is located. > > Yes, the system could be hacked. That’s pretty much the exact risk I face today by having a car that is operated solely by its clicker. I’ll see if I come to regret taking that risk. I work for a tier 1 supplier on automotive electronics. The problem with your idea for existing cars is the remote start receiver and the ECU, while connected by CAN bus, don’t support this functionality. Also, newer cars add CAN gateways (to protect from the Jeep hack). Yes, you could change the code. But for an existing car, the problem is once you develop the software patches, validate them, test them, sign them cryptographic-ally (it can be hard to do on older car lines, especially beyond warranty support), you’ve got the problem that 2-5 separate computers need to be updated to support this feature. Most present cars don’t support network updates (we call them OTA updates) for anything but maybe the infotainment system. And only that if the infotainment system has a cellular radio, some cars don’t. _Tesla_ appears to support updates to any subsystem in the car, and that’s great, but most of the other OEMs don’t. What this means is, in order to update these computers, you have to tear into the car. Down under the dash might be the receiver module for the remote start, the ECU’s in the engine bay, the CAN gateway module may be buried under the dash somewhere else - it’s an absolute royal pain to get to any of this stuff. Some boards may have epoxy on their programmer pins or have a fuse blown to block any future updates and may have to be replaced entirely. Minimum cost, per car, would probably be around $1000. Plus a few hundred k, maybe a few mil, for the software updates, per car line. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [April 6, 2019, 3:18pm UTC](https://boards.straightdope.com/t/law-enforcement-vehicle-chase-quesiton/831822/63 "2019-04-06T15:18:33Z")
> [@pkbites](#): > > I can start, stop, lock, and unlock my truck using my phone or Ipad and the system uses satellite. I could be anywhere on the planet and start my truck that’s parked somewhere else half-way around the globe with just the touch of a button. This all uses the free version of Onstar. It costs me nothing extra. While OnStar uses GPS satellites for positioning, mobile phone/data infrastructure is used for communications. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [April 6, 2019, 4:33pm UTC](https://boards.straightdope.com/t/law-enforcement-vehicle-chase-quesiton/831822/64 "2019-04-06T16:33:29Z")
> [@excavating\_for\_a\_mind](#): > > You don’t have to crack the engine block. All you have to do is penetrate about 0.010" of soft copper (or, more likely in today’s cars, aluminum) tubing. A full-tube leak in a radiator will drain enough of the coolant to prevent proper circulation in a matter of minutes. Once the circulation is stopped, the engine will overheat and either shut down or a component will fail reducing the power and, eventually causing the engine to fail. > > And, it doesn’t even have to be a .22 rifle, I just used that as an illustration. Just a little bit of research might come up with a air-powered device that would shoot projectiles that would be accurate and have enough momentum to break through whatever plastic and whatever else (ac coils, perhaps oil coolers) that may be mounted in front of the radiator. My point is that instead of chasing a vehicle around for hours, it could be disabled quickly. The spike strips do not always work as some tires are not vulnerable to them, and they also require the officers to get very close to the vehicle in order to deploy them. > > As this is NEVER done, although there are certainly situations where it could be done safely and effectively, suggests to me that there are (nearly) universal police department policies against it. I do find it odd that such universal policies (if they exist) can be effective but these same departments cannot figure out how to institute a policy not to shoot unarmed law-abiding citizens. I don’t know. It seemed like they were having a time shutting down the engine of a stationary vehicle with a gun specifically designed for shooting trucks. It’s not surprising that this is “never done” Stopping a car with a rifle would require deploying a trained marksmen to a stationary point along the vehicles route or from a moving vehicle (car or helicopter) in front of the target. Assuming you can make the shot, you have now induced critical damage to a vehicle moving at high speed, which would likely produce unpredictable results. [Previous page](https://boards.straightdope.com/t/law-enforcement-vehicle-chase-quesiton/831822.md?page=3)