Jeleen will mention "a strange hat worn by a strange old man who sang a strange nursery-like song" as part of the investigation, giving a hint that it is Uncle Sweetshare. Going inside the workshop, Uncle Sweetshare can be found. He will gladly admit to his crimes. He can be given the choice of either stopping or being killed. Which ever way chosen, all that is needed is his White Colovian Fur Helm to complete the quest.