Low level white smoke indicates a hobby level. From the smoke in the pictures it looks like a hobby rocket was fired. Very amateurish.
Every army/navy store has hundreds of that modern shell container. Hard to trace. You don't have to give a name or anything to buy one of those tin cans.
This guy/gal is a sure amateur with a decent AM plan.
Not trying to be arguementitive, but do you think a hobby rocket could have produced that much damage to the door?