But what I mean is that sometimes these things can just show up. Who's to say that this wasn't joe somebody's comic. For instance it could be "grandpa's old comic" that they threw in storage without realising what it was worth. If the thief had any inkling of what it was worth, would he really keep it in a storage facility? I can understand him hiding it so they won't find it, but I think a safety deposit box is better then a sliding door protected by a padlock.
Not to mention if it IS his, then whoever owned the room before should be in cuffs.