If you’re not sure if you’re going to get your speed down, this sounds like a very unsafe option to me, because not making the turn tight enough puts you in prime position for a head-on smash.
Less cliched, but also less likely to be done. It’s not a quick thing like cutting a line. It requires getting up under the dash and probably fabricating a piece that will give way. Nevertheless, if one had access to the inside of the vehicle, and time to work unobserved and uninterrupted, it is feasible.
No, that wouldn’t matter. The interlock mechanism is designed so that you can’t take the car out of park unless the brake pedal is depressed a bit. It uses a simple switch activated by motion of the pedal. Whether the brakes actually function or not is irrelevant.
Back to the central notion in the OP, as many have mentioned here brake sabotage is a sloppy way to try to harm someone. There are many ways it could fail. An alternative would be steering linkage sabotage, which could be pretty easily done so that there would be a sudden unpredictable loss of steering control.
Is the sensor on the brakes, or on the brake pedal?
See post #22.
84.06 miles on the Interstate. At least that was my experience.
When they replaced the engine in my car, they must have removed the brake line and never tightened the line to the caliper correctly. I noticed that the brakes were “spongey” right away, but they seemed to remain consistently so at each intersection. It’s a big old car, so the brakes aren’t as responsive as most of us are used to anyway. I followed my girlfriend, and we agreed that I would leave a huge gap between our cars, to accommodate my any brake issues which could “develop.”
We got as far as Indianapolis, and when we tried to take an exit, I was trying to slow down and go down a hill at the same time. She was waiting below at a red light and saw me barreling down on her in the rear view. I ended up going around her and running a red light and worked my way into a parking lot, where I slowly eased it to a stop. I found the brake line leak there, so I rented a U-Haul for the rest of the trip.
I “felt” something wrong early on, but I made the bad choice to leave it and be delicate with the brakes instead. The fact that it was easy to detect makes it a poor method of murder.
If this whole thing sounds like a plot device for a Dukes of Hazzard episode, that is especially the case in this instance. The car this happened with was the General Lee.
Something to keep in mind is that the front and rear brakes on modern vehicles are separate systems for the most part. Each has its own reservoir and set of brake lines. If a front brake lines busts, for example, the rear brakes should still work. (Not well, but they should be able to stop the car.)
Last week this exact thing happened to me. My daily driver is a rusted-out 1991 Pontiac Sunbird. On the way home from work some idiot abruptly stopped in front of me and I had to slam on my brakes real hard. Thank goodness my car stopped in time, but the next time I applied my brakes the pedal went to the floor! At that moment I knew I had busted a front brake line. 
But the rear brakes still worked, sort of. I was able to limp home.
I embarrassed to admit this, but I’m still driving the car w/ only the rear brakes. I need find the busted hose, get my double flaring tool out, and fix the damn thing. Maybe I’ll do it this weekend. Until then I’m dependent on the rear brakes and downshifting the AT for stopping.
Yeah. See, with the front brakes out, if someone cuts your brake line NOW, then you’d crash for sure.
I’ve had brake failure on a 90’s vehicle. I knew I had brake failure before moving the vehicle. The vehicle still started and shifted into gear to move out of the way. Don’t count on it not going into gear, just because you have no brake.
Another missed point is the master cylinder in the brake system can go out. The hydraulic fluid won’t pressurize in the line then. It can fail while driving, and the front and back brakes can fail at the same time. Anybody with a spongy brake pedal, or one that slowly depresses farther as you are at a stop sign, should suspect the master brake cylinder is failing.
Again if you want to tamper with the brake system, and have it fail, add something to the brake fluid that will lower the boiling point. As soon as the brakes get used hard, they will fail. You have the extra added bonus of when everything cools off it all looks normal. Unless you do a chemical analysis of the brake fluid, no one would ever know.
The whole concept of trying to commit murder this way is pretty lame. Even if your victim lived on to of a hill and lost braking, there’s no guarantee that they would die. Everytime I’ve seen this in the movies it shows the driver totallly losing it. In real life people are resourceful, like gearing down, using the E-brake, hitting something before the car gains too much speed, or running against a guard rail, or running along a ditch, there are ways to slow and stop a runaway car.