Here is the full list of all 33 The Painscreek Killings achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Completionist
All Letters Found
Case Unsolved
Derrick Tyler's Story
Charles Roberts' Story
You're Fired
Truth Revealed
Guest's Lost Cap
The Secret Lies With Her
Matthew Brooks' Story
Missing Journalist
Best Friends Forever
Sofia Miller's Story
All Newspaper Articles Found
All Keys Found
All Tools Found
Oliver Gibson's Story
Dorothy Patterson's Story
Wanda Tyler's Story
Steve Moss' Story
Bernard Hopkin's Story
Bloody Knife
Here Lies Sofia
Scott Brooks' Story
Scott's Secrets
The Hidden Truth
Trisha Roberts' Story
Dying Man's Letter
Vivian Roberts' Story
Mary Martinez's Story
Andrew Reed's Story
Tutorial Completed
James Howard's Story