During the attack that claimed the lives of his wife and daughters, Peter was shot in the head, so he has no memories of the murders. In order to cope with the grief, he fabricated a delusion in which his family is still alive and created a new identity for himself based on his inpatient ID band "W1-1L 8-10-10". Once dismissed, Peter moved back to his abandoned house, which is now condemned and covered in graffiti, but in Peter's mind, it is still unspoiled and inhabited by Libby and the girls.
