The murderer was a real piece of crap in general having shot and raped a number of other people among numerous other serious crimes. The case ended up having a lot of publicity at the time with idiots coming to his defense. The accounts I've seen don't have him robbing the grocery store around the time of this incident though and the speculation is that he watched Bobby pay for his groceries with a $100 dollar bill (and possibly he caught a glimpse of the $6,000 wad it came from as well, who knows). At least one witness saw him intently watching Bobby inside the store prior to robbing him just as he left the store.
12ft.io