I have shot two mature deer that I had seen before.
This first one I saw feeding in an alfalfa field the last week of September with three other bucks. I shot him at the same spot one week later after moving my standcloser to where I had seen him.
This second buck I saw feeding in a different alfalfa field while doing some scouting in August. I never saw this buck again until I shot him 3 months later around thanksgiving. I killed him about 250 yards from where I had previously seen him on a trail back in the woods.