I work in a bar downtown. We have a building that we only operate on the weekends and keep literally boarded up during the week because we have been broken into so many times. I was inside doing some work and when I finished, I set the alarm and left. I forgot to do something so I put my toolbox away and returned. Disarmed the alarm and walked in when I heard something from the other end of the building. I just stayed still for a few minutes and there it was again. I moved slightly closer to that area and saw that a light was on, a near necessity since the windows are boarded up if you were going to do something in that end of the building. There was the noise again, I was positive someone was in there. It's a bar area and has been the subject of numerous break in's for the liquor. I drew my P3AT and had an LED 2D cell mag light in the other hand. I crossed my wrists to provide light and sighting for the P3AT. I was calm, not at all feeling nervous which is strange in retrospect. My plan was to hold the guy at gunpoint until the cops arrived. Normally I wouldn't draw without lethal threat but in the case of a break in, the basis of the Castle Doctrine crossed my mind despite the fact I wasn't in my "castle". I rounded the corner on a far axis enough to expose the corner of the bar while I was still in the darkness. The gun was pointed at the base of the bar where it intersects the floor. I did not want to point the weapon until I determined the target was unfriendly. A little farther and then I saw the "perp", a new employee I just hired a few weeks before. He has keys and codes, and works based only on tasks without a schedule hence my not expecting him to be there. Whew! I'm happy to say that I never pointed the gun at him, and I feel like I did pretty well. On another note, I could have just left and called the cops. Maybe I made a mistake in pursueing the possible criminal. I thought I'd post my experience here and see what you guys had to say.