Did He Kill Susan and Tried to Kill John?

Police didn't record a word of their long talk with juliet driscoll. Nobody knows what really happened, except for him and garrett. But remember, garrett copp testified that he was merely christopher's poppet on a string when he killed susan and tried to kill john. How do you get a jury to doubt a statement like that we now had to go after him with hammer and toks? Oh, and he did. Flisher went after garrett.