Will car insurance cover stolen good, while it was under their care?

I had an accident, State Farm towed it to some salvage yard, got it back, camera, registration, spare tire, iPhone charger, battery pack, limited edition pocket knife all gone! Change jar cleaned out, and EZ pass used. I called State Farm, and they are closed. I'm so vexed right now.

Probably not. It is considered the car owner's responsibility to secure their contents before handing the car over to a repair facility.

Now, if you can show that you handed the car over on a given date, and that the EZ pass was in the car and was used by other than yourself, perhaps that might be evidence to use in a civil suit against the salvage yard.

The people at the garage will have taken your stuff with out a doubt
my son's car was hit by a passing car and taken to a garage appointed by the insurance who then wrote the car off
my son decided to let the insurance keep £150 of his pay off so that he could keep his car, and try and get it back on the road as a hobby.
when we went to the garage to pick up his car we found the parcel shelf ha been swapped with a knackered one, his CD player and radio worth £300 had been removed and his brand new battery had been swapped with one that its terminals would not connect to his car.
they thought it would be scrapped by the insurance and no-one would know

In theory, yes. But in practice you can't prove anything except for the use of your pass; sadly there are dishonest people who'll routinely make similar claims for non-existent valuables so insurers won't just take your word.

In any case, when a car is left anywhere for repairs or towed away the owner is expected to remove all of their possessions. Although when a car has been badly damaged in an accident and gets towed straight away from the scene that's not always immediately possible, especially if the occupants are having emergency treatment or assisting police with their enquiries.

Definitely try and claim though: even if refused it may alert them to a pattern of similar complaints from others who have had the same experience with that particular towing company or body repair shop. One problem through is that straight after an accident vehicles are insecure and there's a lot of confusion at the scene: there are plenty of opportunist thieves who take advantage if they come across such a scene to steal, so those who you presently suspect may be innocent and if not they may well claim your stuff was gone before they took the vehicle away.

So your chances of a successful claim are very low but that does not mean you shouldn't report the theft anyway and preferably to local police just so it's on record and to help if they ever recover your property.

Actually it wasn't under the insurance companies care, although they can probably help you with your claim against the tow yard it was impounded in, Problem is the tow yard will claim none of that was in the car when it was towed to them, and it's going to be hard to prove what was in the vehicle, and at what point it went missing.

I hate to see those things happen, when I was running my yard I let nothing in without doing inventory if another tow company brought it in, and if they wouldn't sign off on the inventory I refused the vehicle. When picking one up after a vehicle I insisted the office on scene sign an inventory, and I would not drop one off to a closed business, but I saw a lot of things going on with others.