Visible crew/equipment: Marge receives the call after the execution (the first call), waking her up. The camera tracks toward the bed, and its shadow is visible on the right side of the screen.
Visible crew/equipment: When William H. Macy drives past the parking garage security guard, who has just been killed by Steve Buscemi, in the shot of Macy's car moving across the screen you can see a crew member holding equipment reflected in the car window.
Answer: While there is nothing in the film that explains this, the most likely step taken by the authorities would have been to see whether Jerry and his wife had made out an will and who they would give legal custody of their son if anything happened to them. If there was no will then it's likely the closest family or relatives would be asked to take custody.
Lummie ★
He probably still has Lundegaard Grandparent (s) and a grandmother from his mother's side - any of which could and would become his legal guardian (s).
KeyZOid
He'll be a rich man. Grandfather said early in the movie that his daughter and her son would bever have to worry about money or words to that effect.