"after they ( Boone and Weitzman) discovered the carcano beneath the pallet of boxes they stayed right there and waited for Fritz and Day to come to the site."
Have you read the "supplementary investigation report" below?
Let me help you with a quote from it.
"Deputy Boone called out that he had found the rifle shoved down between 2 rows of pasteboard boxes of books. Capt. Fritz took over the search at this time and one of the other Deputies who had been in the building came and told us that Sheriff Decker had given orders to let the City take over the investigation and for the Deputies to return to the sheriffs office, which we did."

"Deputy Boone called out that he had found the rifle shoved down between 2 rows of pasteboard boxes of books. Capt. Fritz took over the search at this time and one of the other Deputies who had been in the building came and told us that Sheriff Decker had given orders to let the City take over the investigation and for the Deputies to return to the sheriffs office, which we did."Deputy Boone called out that that he had found the rifle...... Actually it was Weitzman who first spotted the carcano on the floor beneath the pallet of books but Weitzman was down on his belly shining his flashlight beneath the pallet and Boone was standing up on the West side of the rifle beneath the pallet. So Boone yelled out that they had found the rifle) Fritz came over to where Boone and Weitzman were and took charge ...... Fritz took over at this time ....
Isn't it clear to you that Tom Alyea filmed Detective Day as he lifted the MANNLICHER CARCANO from the floor.....