I'll try a hand at organizing your investigative pairings. I'll give little blurbs about why I chose to place them this way:
Investigator Pairings
Bus Driver/
Arsonist/
Kidnapper
(Your target owns gasoline.)
Amnesiac/
Survivor/
Witch/
Electro Maniac
(Your target is a loner and seeks solace only with themselves.)
Cop/
Insane Cop/
Executioner
(Your target seeks justice.)
Doctor/
Coroner/
Cultist/
Soul Thief/
Janitor
(Your target works with the dead.)
Investigator/
Journalist/
Corrupt Journalist/
Consigliere
(Your target handles sensitive information.)
Gun Smith/
Veteran/
Vigilante/
Arms Dealer/
Mafioso
(Your target owns a fine selection of weaponry.)
Escort/
Jester/
Consort
(Your target enjoys occupying others at night.)
Citizen/
Mason/
Ravager/
Godfather
(Your target seems otherwise ordinary...but may be hiding a dark secret.)
Detective/
Lookout/
Actress/
Framer
(Your target's intent is to perceive or deceive.)
Businessman/
Student/
Drug Dealer/
Lawyer
(Your target likes to make offers and promotes learning new tricks.)
Armoursmith/
Bodyguard/
Blackmailer/
Fabricator
(Your target offers some form of protection.)