This is a description of a patient, let’s call him John, whose FTD was confirmed by court-ordered testing. John, sixty, was a former college professor with no previous criminal history. Since his mid-fifties, John’s behaviour had changed significantly and had been getting progressively worse. He intruded into other people’s conversations and walked into offices that he had no business entering. He constantly stole things. In restaurants, he would fill his pockets with sugar packets and napkins, and at one point he had a collection of twenty-eight umbrellas that he had stolen. He ate indiscriminately, even going through waste containers and eating garbage. His increasing sexual demands of his wife, combined with these other changes, ultimately ended in their divorce. He then began stalking children. He followed children home from school…