Ok, so I was doing the Nuevo Paraiso barrier glitch on single player and when I was running allong the barrier I found this mexican. I nicknamed him "Mysterious Bush Mexican" because I found him in a group of bushes. I was unable to walk up to him due to the invisible barrier. I didn't try to shoot him because I didn't think about it.
Here is a link to the video that I used to help me get up to the barrier. Nuevo Paraiso Barrier Glitch Video
Here is the video and a pic of this "Mysterious Bush Mexican"thumb|right|300px|Mysterious Bush Mexican