How many catalytic converters can you steal while riding a bicycle? Sort of like the guy who was found at the bottom of the river wrapped in 20 feet of log chain- - - - - - -"Dam fool stole more chain than he could swim away with!"
They could ride out there and steal the cats, and hide them in the woods, and then return at midnight in the pickup and load them up. It is hard to imagine what else of value would be in a junkyard.
