The talk show host Marty Clark says that David Murch's brother Phillip is buried in "Silver Springs, Maryland." Although commonly but mistakenly called "Silver Springs," the city is actually "Silver Spring."
When young David shoots his brother there is no recoil of the gun. A small child should have felt the recoil very hard and moved his arm but in that scene the gun didn't move his arm at all thus proving it's not real. The same problem appears in the scene where David shoots Jane.