Where were the cops?
1) Jerry blows up the house using the gas line.
2) Charley and the others flee the scene by car. The car gets wrecked and they steal the car of the unfortunate guy who came across the scene, and leave theirs behind.
3) Charley's mom checks into a hospital.
4) Charley goes back to the neighborhood, and no cops are at the scene of the burned down house.
Many people have already disappeared or been found dead. The cops are surely already looking into this. Then a house burns down, a destroyed car is found on the highway, a dead man is found next to the car, the dead guy's car is stolen, and then the mom of the number 1 suspect checks into a hotel. There should have been police swarming to get her when she checked into that hotel, and police staked out all around the house that next morning.