Each character should have their own ability that corresponds to an existing mechanic from HN1. For example:
Gerda: Can throw pastries at the player if she gets angry enough, thus temporarily blinding them like the tomatoes in HN1.
Otto: Already has his gun which functions exactly as it did in HN1.
Mayor: Already has a security system that is currently unused in the files.
Peterson: Can throw jars of glue at the player like he did in HN1.
Guest: Should have his stalking mechanics from HGP.
That just leaves Nielsen and maybe Leslie, but I'm not sure what mechanics they could/should get yet. Leave a comment if you have a suggestion.