If the kid took the family car and ran people over would the parents be responsible for that?....it’s a slippery slope that’s for sure.
"It depends" on facts not in your hypothetical.
This case will turn on the application of criminal negligence in Michigan law. Fiver government officials were charged with this for the Flint water situation.
The jury will decide first, and appellate court of Michigan Supreme court will get the last word if it wants it.
Civil negligence holds us to behave in light of reasonably foreseeable consequences. The law does not expect us to be perfect (at least not in principle), but does expect a certain amount of care.
Also in civil law, as close as it gets to criminal negligence, is a punitive damages award. The standard for this, on paper, is acting in wanton and reckless disregard of the well being of others.
The jury is in a position of being allowed to second guess, as the jury is supposed to reflect society sensibilities. They will have to find "something" in the parents head - what did they know? and what did they do about it?
Back to your hypothetical - if your kid has a habit of taking the car and driving recklessly, and you know that, then you best make an effort keep the keys away or otherwise disable the car. I do wonder how many kids make death threats. The number of bomb threats to schools is thousands a year. I would guess the number of kids expressing death threats is millions.
Depends. Did the kid steal the car or did the parents give him access to the car. Now use that logic in this case.