They definitely asked for permission to run the serial numbers. If I had of told them no would it not give them probable cause with that answer?
No.
For instance I've had a cop pull me over an asked "would you consent to a search of your vehicle" and I told him no there wasn't any reason to. He then went on to say "well what are you trying to hide?" I answered nothing, and he responded "then why is it a problem for us to search your car?" So I said here search it clean the trash out of the back while your at it. I had nothing to hide but it seemed impossible to prevent him from gaining probable cause to search the car.
He just badgered you until you gave in. In that situation, the cop might threaten, lie, and say all sorts of BS to intimidate you into consenting. Don't ever consent. Be polite, but firm. Just keep repeating over and over "I do not consent to a search. Am I under arrest or am I free to go?"
Don't answer the cop's questions. Don't get into a conversation. He is trained and experienced in verbal judo. You aren't. Whatever he says, whatever he asks, either don't say anything or respond "I do not consent to a search. Am I under arrest or am I free to go?"
Don't resist him if he says he is going to search anyways, but don't consent. He might decide to search without consent if he thinks he has probable cause. If you do not consent to a search, then your attorney has an opportunity to argue that the officer did not have probable cause and possibly get the evidence thrown out. If, on the other hand, you consented to the search, even if he had no probable cause you are now screwed -- your lawyer probably can't get the evidence thrown out.
Some folks might think "I've got nothing to hide, why not let him search?" There are a couple reasons. First, while the vast majority of cops are good people doing a hard job, there are a few who are not. As an example, the Utah State Troopers just fired a trooper because she had been arresting people for DUI who hadn't even had anything to drink. She made it all up. If an officer is never in your car, it is harder for them to claim that they found something in it.
Second, if you don't insist on your rights, you lose them. We have the right to be free of unreasonable searches and seizures. Searching a car as a routine part of a traffic stop is the very definition of an unreasonable search. An ATF agent who has no probable cause to assume that you have committed a crime asking for the serial numbers of every gun you won is yet another example of an unreasonable search. You shouldn't have even answered him "yes" or "no." You should have only answered "my attorney is John Dewey of Dewey, Cheatum, and Howe."
Ordering a pile of ammo isn't a crime nor is it probable cause to assume that you have or will commit a crime.
I obey laws. I don't drink. I don't use illegal drugs. There is nothing illegal in my 4Runner. But I will never consent to a search.
