Every place I have stayed at, the maids are happy to have one less room to clean when the guest puts this on the door: 
And just how many suitcases did he have there? 20? If these firearms were assembled when he was found dead, they may have been just laying around for days. Wouldn’t room service think something was up?
I know, lots of questions with no answers.
Anyone who stays in hotels understands that the "Do not Disturb" sign hung on the door will keep all maid service out. I know people who leave it on all week and don't ever have maid service.
Every place I have stayed at, the maids are happy to have one less room to clean when the guest puts this on the door:
um... the dude could legally carry 2000 guns into that room!
Maybe he was a gun dealer going to a gun show, or about to give a presentation on military weapons, or was a gun collector about to sell his entire inventory, or 1,000 other things.
The guy did nothing wrong carrying some guns up to his room.
What part of "Do not disturb", don't you understand? The housekeepers love that sign, less work for them, and they usually get a nice tip when the guest checks out. Room service just knock and say "room service", which is how the guest ordered the food to the room service operator.
You have never stayed or work in a hotel from my summation.
Also, getting all that stuff up to his room, find a bellman with a bell cart, tip $100 and no questions asked.