It’s a warm, winter morning in Roseville Square as police officer Dave Flood approaches a man panhandling at the windows of cars coming out of the shopping center. Allan Havercamp, 36, is a train-hopper: With a dusty, sky-burnt complexion and a towering Army backpack, Havercamp holds up a cardboard sign that reads, “United States Drifters Core: Parasites Never Die!”

            The sign has the coded insignia of boxcar transients on its corner — a hidden message to anyone who speaks the language.

            Havercamp is originally from Texas. By his own reluctant account, the rails have already taken him from New York to Florida and beyond. Havercamp inhabits a multi-faceted world on the tracks, one peopled with young thrill-seekers and untraceable criminals alike: Not telling the difference between the two is believed to have cost Alpert his life.