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