So, in A Storm of Swords, Joffery states that he isn't a stranger of Valerian Steel and this causes Tyrion to suspect him of sending the catspaw to kill Bran. He mulls it over later and goes through what he knows but is unable to come up with a possible motive for Joffery. But later Jamie, after making it back to Kings Landing, asks Cersi if she sent the catspaw, she says she didn't but does say that Robert believed Houses should be given the right to kill their disabled children, so Jamie deduc