I did everything in order by wikia sits, got dagger, red pot, and thread in window, investigated dog gate, grabbed other 6 silver items, didn't the printing with flour fly, and fly paper, found it was Frank, talked to poison salesman, asked Frank why he bought, checked grate, talked guard. Nothing works. I repeated the process even backtracked few hours. He just keeps saying I still haven't found who did do it when a prompt to click who did should be appearing. When I repeat printing it says ' you have already found the culprit'
my char is: Ambard

Please help, I cannot start Legends quest without the 3 points from this one.