He was going to ambush six police officers who had their guns aimed at him with a pellet gun that was in his room?
Perhaps your post was meant to be sarcastic? If not let me explain a few things to you.
First you need to look up the meaning of the word ambush.
Next, yes Shaver was in AZ working for a TX based pest control company. But he wasnt doing normal pest control, i.e. spraying, setting mouse or rat traps, etc. but his job was go into big box stores like Walmarts, Lowes, etc. and sometimes, if other methods failed such as netting, shooting birds that had become trapped inside by shooting them with a pellet rifle, hence the reason he had a pellet rifle.
Here is a job description I found for one such job. Note that one of the qualifications is An appreciation of hunting, fishing and trapping.
https://public.businessbymiles.com/Job?LinkID=188fa7cb-e2e7-4a2f-b945-102ba4f54b0b
If you dont think birds are a problem inside stores, watch this.
Customer captures bird on video inside Walmart eating food for weeks
Last, if he was conveying money or drugs for the cartels, he would have to be the stupidest drug runner in the history of the world to only be armed with a pellet rifle. Not to mention that if Shaver had been involved in any criminal behavior or had anything more than a pellet rifle in his room, that would have been brought up at trial to be sure.