I just talked to my mother whilst translating one of her emails into english, and described that passage about Z and the cats and his death.
And out of nowhere she sais "That sounds an awful lot like a Werewolf to me."
The wolf surrounding with cats (or is it a were-panther?) - the wolf among sheeps, the marks could be OF HIS ORRIGIAN / a symbol for him being a soldier/killer/madman/maniac/Johnny real father M.I.A.
The police did not see the marks, yet Johnny did.