Okay, I think I already know the right answer, but I'd appreciate anyone's advice or input on the subject before I act.
Recently I've started a new job. In a nutshell we set up and maintain cameras on mostly school campuses around the state. I've been working the job for less than a week. Me and my lead have worked by ourselves, together for all 2 of the days I've worked 'on-site'. The following took place on my second day of work:
The day started at the office, we loaded up our tools and drove to a job site / k-6 school a few miles out. After meeting with the school's front desk, my lead had someone from the school open the server room (located in the corner of the school library) so we could use our computes to set up some new camera installs. We put our equipment and bags in this room, propped the door open, and continued with our work. Later on, we were doing some diagnostics in another exterior TC (telecommunications closet) when my lead sent me back to the first room to grab a tool from his bag. As I looked through his (rather large) backpack, I noticed a holstered 'glock-style' handgun amongst his gear. A small flicker of panic hit me, but in the moment, I thought 'oh, so he's just that kind of guy' and put it out of my mind. Having not been able to identify the piece of equipment he sent me to fetch, I picked the bag up and took it to him. We carried out our work like normal and I didn't say anything about what I saw in his bag.
Today, my friend/co-worker who helped get me the job, came back from a side job / multi-day site. As we caught up, he asked me what I thought of all the people in the office and the guys I've been working with. I explained to him that my lead was okay on a professional level, that he was smart and thorough and seemed good at what he did, and that I typically got along with him, but he seemed a little strange and off-putting in his social skills. I told him about what I saw in his bag, and his reaction soured. He thinks I should tell my supervisor, on grounds that it is illegal to carry inside school premises, and even though it probably isn't dangerous, it could be damaging to the company if he is ever found out, and we could end up losing contracts in the school districts. I agree on these points, but it is a hard call to make, as I might be working 1 on 1 with my lead for the next few projects and I don't want to over-react or fink on a co-worker. Then again, he might be fired. Should I get someone fired over having a gun inside a zipped up backpack in a holster inside a school? It's not likely, but it is possible that a kid at some point could get sneaky and curious and invade the bag. It's also not likely but possible that a teacher or staff member could notice it at some point and damage our company reputation and harm my way of life as well as my team's. If anything happens concerning that situation, from here on out it is going to be partially on my hands. My friend who has worked with the company 2+ years says I shouldn't hesitate, my wife agrees. I'm probably going to end up talking with my supervisor, but I don't want to have an altercation with my lead, especially the kind of person that I work alone with, has a gun, and I'm threatening his way of making a living. Ugh, I hate to be in this situation, I'm damned if I do, damned if I don't.
Does anyone have any thoughts, opinions or advice on this subject? I won't be doing anything probably until Monday, unless I make a snap decision and just call my super's cellphone and address the issue that way.
Just, ugh. Two days into a new job and I'm already having shitty drama.

