In 1994 I worked graveyards at a convenience store/truck stop just off I-40 in Tucumcari, NM. I worked the gas side, while I had a partner who worked the diesel side. We had showers in the back for the truckers so there would be people going in and out at all hours of the day. One night about 1:30 am I checked one of the security cam monitors and noticed a guy staring at me from down one of the aisles. I didn't let on I had noticed him and just kept glancing at the monitor. After a minute or two he went to another aisle and started staring at the diesel side attendant. Suddenly someone came out of the showers in back right behind him and he got really startled and started acting nervous, his attention switching between me, my partner, and showers. After about 2-3 minutes he seemed to change and then slowly wandered out of the store. About 3 hours later we heard sirens. Dozens of sirens. More sirens than should have even been in Tucumcari. They were coming down the road into town. A few people came in and mentioned there were a shit ton of cops at an Allsup's convenience store about 4-5 blocks towards town. The news the next day announced someone had gone into the Allsup's about 2-3 that morning, forced the lone female attendant into the freezer in the back and then shot her execution style, twice in the back of the head. Police never caught the guy who did it, but they did have our security cam footage and listed the person I mentioned as a person of interest. I can't help but think the guy was connected to it and he came to out store first but gave up after seeing too many people there.