I'll admit I haven't read this entire thread. So perhaps there's more info here than what I'm replying to.
Overall, it's just good practice to remain as far away from any domicile as possible. If I were so limited in my flight right outside of my home, personally, I wouldn't fly there. Also, I believe every word the OP posted in his initial post. There are MANY people out there who wear tinfoil hats and think the world is spying on them. They could easily become convinced the OP is a government agent posing as a civilian in an effort to gain information about their lifestyles. I've met my fair share of these types in the years I've been flying R/C aircraft. Even more so since mounting cameras on a couple of my aircraft. They simply cannot believe that you aren't capable of reading the serial number on a dollar bill from 50 meters away. I have a very simple way of dealing with such people. I take my laptop with me every time I fly and here's why.
Roughly 18 months ago, while flying one of my heli's with a cheap, 2mp camera on it that was recording video, I had the cops called on me and a lady accused me of taking video of her laying out nude in her back yard. A yard that at my closest approach, was over 25 meters away although I was in a soccer field within 25m of her fenced in back yard. My flight path was directly away from her house as I was doing some video of the local YMCA for a friend who worked there as a maintenance guy and he was wanting to know what shape the roof was in after a bad storm.
She approached me from behind, wrapped in a robe and wearing some slip on shoes, while the heli was still in the air. Being used to people walking up to me to ask about my aircraft, I quickly looked at her and realized her body language was of the ill tempered type. Still, that realization couldn't help my heli because as soon as it landed, she kicked it.
Her foot was cut and when the cops showed up, she accused me of having "flown the thing into her". The cops had showed up within a couple of minutes after she kicked it and I went toe to toe with her calling her a liar. Longish story shorter, I got out my laptop, I was using it to transfer video from the 512mb Micro SD card to the laptop to make room for more video on the SD card, and plugged the SD card into the adapter and then showed the cops exactly what had happened. Before ever removing the SD card, I established with the woman, in front of the cops, that the aircraft had been airborne the whole time until she kicked it upon landing and that I had not approached the heli until that moment. Since I always land nose in when wind allows, the heli picked up her approach and kick. It also showed that at no time had it recorded her laying out nude in her backyard. She also said on more than one occasion that I wasn't just an Army guy, I lived about six houses down from her so she had seen me outside in my uniform, but a SPY for the government who thought she was anti-government and a threat to the POTUS.
I pressed charges for making false claims of a criminal nature and she was prosecuted, and convicted, of filing a false police report, damage to private property and issuing false claims of criminal conduct. She received one year probation and was ordered to pay for my $500 heli investment.
This happened in LA. Lower Alabama.
Fortunately, and I do not advocate the growing of illegal substances in ones home or yard...just for the record, but that is none of our business nor that of the police if a person hasn't given the authorities any reason to search their home and/or property. At this point, with the information given in the initial post, there is no avenue that would lead to the cops being granted a search warrant.
The gun and knife were in the mans hand/truck. That is ALL the authorities have the right to search. If the OP was the only one who could give an eyewitness account of the gun, then there isn't a gun in the equation unless there is some type of video footage, other witness or, the idiot implicates himself. The cops cannot just search the mans truck on his property with a warrant or otherwise based solely on the word of one person saying he pulled a gun. Especially if said idiot has the mental capability to know his own rights.
Even if said idiot were to admit to pulling out a gun, if the gun isn't in his truck then the cops will need a search warrant for the home. If this idiot has any common sense at all and IS doing something illegal in his home, he will offer the weapons up to the cops upon initial contact which will, in all likelihood, prevent such search. If the idiot has a criminal history of displaying weapons in a threatening manner, then a judge would be much more likely to issue a search warrant.