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
Truth Revealed
Case Unsolved
All Letters Found
Missing Journalist
Bloody Knife
Bernard Hopkin's Story
Derrick Tyler's Story
Dying Man's Letter
All Keys Found
Best Friends Forever
All Tools Found
Oliver Gibson's Story
Wanda Tyler's Story
Sofia Miller's Story
Dorothy Patterson's Story
All Newspaper Articles Found
Steve Moss' Story
Here Lies Sofia
Scott Brooks' Story
Scott's Secrets
Trisha Roberts' Story
Charles Roberts' Story
The Hidden Truth
Matthew Brooks' Story
Vivian Roberts' Story
The Secret Lies With Her
Mary Martinez's Story
Andrew Reed's Story
You're Fired
Guest's Lost Cap
Tutorial Completed
James Howard's Story