Assuming you're talking about a parking lot situation, generally there is no way to establish fault in such an incident. Unless you're a fan of the old "Brady Bunch" TV series. A 50/50 fault, where each driver pays their OWN repair costs.
In situations where a car rolls back into a stationary vehicle behind, it is the front car that is liable regardless of how close the rear vehicle was behind. In the absence of any independent witnesses however, it is often difficult to prove a situation such as this, unless the owner of the forward vehicle willingly admits liability.
The vehicle rolling backwards is the at fault vehicle, in most cases. We were taught in drivers ed to stay far back enough to see the bottom the the wheels of the car in front of you, incase this were to happen to us. If they rolled back a few feet it would be our fault, but if he was warned with the sound of your horn to stop, and still hit your car, then it would be his.
both of you for not looking back
If you back into a car you are at fault, especially if the other vehicle was parked. You are the one with the responsibility to look behind you and to avoid the accident. If both cars are moving all bets are off.
Backing up--it is your fault.
As a general rule, a parked or stopped vehicle is almost never at fault for an accident. The onus is on the driver of the moving vehicle to make sure the way is clear.
The owner of the car that caused the damage. They have a duty to engage their parking break.
you are if your vehicle hit the other vehicle- you have too many mirrors on your vehilce not to notice another veh right beside you or behind you.
Normally the car that hit the other car is going to be at fault. The vehicle behind you was obviously too close and was not following at a safe distance that would allow him to stop if you did. The police should have issued him a ticket.
If they wern't going backwards when you hit them you are at fault.
In almost every case of a rear end collision, it is the fault of the car behind. The law in all states implies that the driver of a vehicle should always be in control. The assumption is, that rearend collision can be avoided if the driver had been paying attention and not following too close.
Answering "Pulling out of a parking lot onto a street and you have to back up to avoid on coming car and the car behind you hits you who is at fault?"
it is ALWAYS the fault of the backing driver. They bear the responsibility to make sure they can back with safety.