My top three lessons from this story when selling a gun to a stranger.
#1. A SCHOOL parking lot is a horrible place for a gun sale mainly because having it (the gun) there is illegal.
#2. Never conduct a sale at night, conduct it during the day in a very public place. Criminals are for the most part cowards, they look for an easy getaway. A busy parking lot does not afford them that opportunity.
#3. Never go alone. Ever. Take a buddy or two, preferrably armed and open carrying, goes back to the criminals being cowards thing.