Christopher’s kill kit includes his murder weapon and clean-up supplies. At the end of Christopher’s storyline, after he dies, the point of view shifts from Christopher to Amy. She has just used Christopher’s own murder weapon—the cheese wire garrote—to kill him. She then cleans up the murder scene with supplies from the kit. This symbolizes the fact that she, much as she tries to deny it, shares his ability to kill in cold blood. She isn’t motivated by emotion as Ellie is when she kills Tim, nor does she desire attention like Christopher. Amy coolly recognizes a social responsibility to eliminate a threat to public safety. Christopher will always threaten that safety. Even if she could keep him in check, if anything happened to her, he might revert to his former behavior. In addition to the public safety issue, she ultimately can’t trust him not to harm her if theirs is one of the false Matches, and if his crimes are discovered, her career will be ruined, so her motive is partially self-interested.