Here is the full list of all 18 Interrogation Files: Port Landsend achievements.
Discovered the drifter's real name.
Unlocked the second character.
All characters unlocked.
Details matter.
Uncovered a unique hobby...
Some say death is only the beginning.
If the glove fits...
Where there's a spark...
Searched for a bad word in Search.
Watched credits.
Watched 90% of videos for two characters.
Watched 90% of videos for four or more characters.
Watched 100% of videos for one character.
Watched 100% of all videos.
Accused Collaborators.
Accused at least one Main Perpetrator.
Accused All on Accuse screen.
Closed the Accuse screen without choosing anyone.