1) What percentage chance do you want the gun to fail shooting when someone is threatening a family member
2) Would you buy a gun that unlocked with the same percentage (and time) as your current generation cell phone
3) If a gun fails to fire because of a safe lock - who should be responsible for its failure?
There are already trigger locks that do what you want, there are safeties to take care of the gun when the trigger lock is removed. People that actually know gun safety and have trained the people around them don't see the problem. Those that haven't think a tech solution will work - it won't