Hi, this is "guide" to help you achieve 100% collectibles

I will provide here some information that I found online (with its sources), and some links to point you in the direction that I used to achieve the 100%.

In my play stile, I tried to find the collectibles myself first and then check against a list of some kind to see if I didnt missed anything.

I also did found out that there are MISSABLE COLLECTIBLES and if you care at all about the GOLDEN BADGES on the Cases Files, you cant get ANY guesses wrong in a investigation, at this time I followed the walkthrough guide to choose the right answers.
[https://www.ign.com/wikis/murdered-soul-suspect/Walkthrough]
its a "nice" guide, I used just to get the right answers, you can restart a checkpoint if you guess wrong but after sometime it just gets annoying because some checkpoints are really far, and if you mess around trying to figure out the answer by trial and error, you can end up getting a checkpoint on a right guess and having to RESTART THE GAME to get the Golden Badges.

By the end of my Playthrough I found a better one, but I cant confirm because I used the first guide, but this one does seams better with pictures and and answers (especially in the museum that the IGN guide is missing part of the answer)
Guide and Walkthrough (PC) by nyiaor
[https://gamefaqs.gamespot.com/pc/703517-murdered-soul-suspect/faqs/69443]

Guide Picture source: 100% Achievement Guide (by THN)

I started looking for maps about the collectibles of Murdered: Soul Suspect.
I found some right here in the Steam Guides Forum
https://test-steamproxy.haloskins.io/sharedfiles/filedetails/?id=267868862
But to tell you the truth I couldnt make heads or tails of those maps

So I continued searching and I found a Collectibles Guide
Murdered: Soul Suspect - Collectibles Guide by Harry94_ [www.playstationtrophies.org]
[https://www.playstationtrophies.org/forum/topic/221725-murdered-soul-suspect-collectibles-guide/]

It started nice, enumerating the collectibles in each section of the game

Originally posted by Harry94_:

1. Apartments - 14
   
2. Church - 20
   
3. Police Department - 37
   
4. Cemetery - 28
   
5. Asylum - 25
   
6. Museum - 31
   
7. Church Revisited - 2
   
8. Town - 61
   
9. Judgement House - 24

Total - 242

But after the first 2 section it just becomes a redirection guides to the collectibles videos

Originally posted by Harry94_:

Apartments

1. A Watery Grave
   
2. A Watery Grave
   
3. Info About My Killer - Warning Poster
   
4. Info About My Killer - News Article #1
   
5. A Watery Grave
   
6. Ghost Girl's Messages - Gallows
   
7. A Watery Grave
   
8. Julia's Thoughts - Lillian and Lillian
   
9. Ghost Girl's Messages - Coffins
   
10. A Watery Grave
    
11. A Watery Grave
    
12. Profiler's Memories - Concern for Joy's Safety
    
13. Julia's Memories - Meeting Ronan's Parents
    
14. A Watery Grave

Total - 14

Originally posted by Harry94_:

Church

1. The Bell Tower Banshee
   
2. Julia's Thoughts - Second Time's a Charm
   
3. Salem's History - Organ Dedication Plaque
   
4. The Bell Tower Banshee
   
5. Salem's History - Burned Rectory Plaque
   
6. Julia's Thoughts - Can't Stop Loving Him
   
7. The Bell Tower Banshee
   
8. Julia's Thoughts - Ronan's Fedora
   
9. My Life - Marrying Julia
   
10. The Bell Tower Banshee
    
11. The Bell Tower Banshee
    
12. The Bell Tower Banshee
    
13. Salem's History - Rectory Dedication Plaque
    
14. The Bell Tower Banshee
    
15. The Bell Tower Banshee
    
16. The Bell Tower Banshee
    
17. Ghost Girl's Messages - Dunking Chair
    
18. The Bell Tower Banshee
    
19. Ghost Girl's Messages - Demons
    
20. The Bell Tower Banshee

Total - 20

Dont get me wrong, I did use the Video guides to check each one of the collectible I had missed, the Artifacts dont have a respective number, so you need to compare by locations.
[https://www.youtube.com/playlist?list=PLSz08HX7PxlUsJDHslwtFM7PFlqi4vZY3]
https://www.youtube.com/watch?v=Shex1F34lO8&list=PLSz08HX7PxlUsJDHslwtFM7PFlqi4vZY3&index=1

This Guide is also were I found warnings about the Missable Collectibles

Originally posted by Harry94_:

Museum
Warning: Eveything in the Museum is missable! Make sure you get everything before leaving.

1. Salem's History - Train Station Memorial Plaque
   
2. Terror on the Tracks
   
3. Salem's History - Dunking a Gossip
   
4. Witch Trial History - Witchcraft Superstition Plaque
   
5. Witch Trial History - German Witch Trial Plaque
   
6. Witch Trial History - First Witch Execution Plaque
   
7. Julia's Thoughts - Ronan Meets Rex
   
8. Julia's Thoughts - Museum Date
   
9. Terror on the Tracks
   
10. Salem's History - Baker in the Stocks
    
11. Terror on the Tracks
    
12. Terror on the Tracks
    
13. Terror on the Tracks
    
14. Terror on the Tracks
    
15. Terror on the Tracks
    
16. Witch Trial History - Witch Trial History Plaque
    
17. Terror on the Tracks
    
18. Terror on the Tracks
    
19. Terror on the Tracks
    
20. Terror on the Tracks
    
21. Terror on the Tracks
    
22. Ghost Girl's Messages - Mansion
    
23. Terror on the Tracks
    
24. Profiler's Memories - Museum Spirits
    
25. Terror on the Tracks
    
26. Salem's History - Museum Donor Plaque
    
27. Witch Trial History - Medieval Witch Book
    
28. Terror on the Tracks
    
29. Witch Trial History - Prayer Book
    
30. Witch Trial History - Book of Engravings
    
31. Ghost Girl's Messages - Caught

Total - 31

Originally posted by Harry94_:

BEFORE Judgement House
Warning: Completing Judgement House won't let you return to most places in Salem, mainly the museum. To be safe, only enter the Judgement House when you have every other collectible.
You should have these collectibles before entering:

35/39 Info About My Killer
34/38 Julia's Thoughts
5/6 Profiler's Memories
22/25 Salem's History
8/9 Witch Trials History

BUYER BEWARE there is a little bug at the Judgement House 1st investigation! Made me lose my Golden Badge, more about it in the Final Thoughts Section.

But after all that I still had some collectibles missing which complicate things, with what I had in hand, I needed to go back and check each place following the video guides to find what I was missing; thats when I found this Guide and Walkthrough (PC) by nyiaor [gamefaqs.gamespot.com]
[https://gamefaqs.gamespot.com/pc/703517-murdered-soul-suspect/faqs/69443]

In this Guide there is a Collectibles Section where it shows ALL the collectibles in order and where to find them (just be on alert about the 2 collectibles on the Church Revisited, the guide doesnt says is the revisited version; Revisited Church is a Later chapter in the game different from the first time you step in the Church)
Some Locations have a "Map Marker" e.g.: R18; I didnt read the whole guide to know what nyiaor is referencing

Armed with this guide I just checked against my collectibles to see what I was missing, and use another video guide to find exactly where I needed to go; Just search the name of the collectible that you are missing on the list, remember that Youtube doesnt load ALL the list if you dont scroll to the end.
[https://www.youtube.com/playlist?list=PLJeA4DU1_rZ5xWaCOXnP8LuaCG87pWDCa]
https://www.youtube.com/watch?v=OmGv6pZkLFo&list=PLJeA4DU1_rZ5xWaCOXnP8LuaCG87pWDCa&index=1

there is a character limit on the guide sections.

Originally posted by nyiaor:

There are 242 Collectible artifacts
(14) Ghost Abilities
(7) My Life
(39) Info About My Killer
(38) Julia's Thoughts
(2) Rex's Thoughts
(2) Truth About Baxter
(6) Profiler's Memories
(23) Ghost Girl's Messages
(8) Ghost Stories
(25) Salem's History
(9) Witch Trials History

Ghost Abilities

1. Pass Through - Ghost Playground Ghost Girl Investigation
   
2. Possess - Ghost Playground Ghost Girl Investigation
   
3. Investigative Skill - Ghost Playground Ghost Girl Investigation
   
4. Peek - Street Investigation
   
5. Escaping Demons - Apartments 2F South Stairwell
   
6. Approaching Demons - Apartments 2F South Stairwell
   
7. Executing Demons - Apartments 2F South Stairwell
   
8. Reveal - Ghost Playground Ghost Girl Investigation
   
9. Touch - Apartments Apartment 4A Investigation
   
10. Cat - Church Rectory 1F
    
11. Poltergeist - Apartments 2F South Stairwell
    
12. Distracting Demons - Church Nave
    
13. Teleport - Cemetery Quarantine Building
    
14. Remove - Ghost Playground Ghost Girl Investigation

My Life

1. Marrying Julia - Church Nave
   
2. Seeing My Own Corpse - Police Station 1F Holding Cells and Morgue
   
3. My First Crimes - Police Station 1F Holding Cells and Morgue
   
4. When Baxter Tried to Threaten Me - Police Station 2F
   
5. The Picture at the Beach - Salem R18 Beach Dock
   
6. The End of "Forever" - Salem M9 behind the Apartments
   
7. Beatdowns - Salem Ghost Playground

Info About My Killer

1. News Article #1 - Apartments 1F Hallway
   
2. Warning Poster - Apartments 1F Hallway
   
3. K. Douglas Personal Info – Police Station 2F Rex Reyes's Office
   
4. K. Douglas Police Progress – Police Station 2F Rex Reyes's Office
   
5. C. Nelson Personal Info – Police Station 1F Holding Area
   
6. C. Nelson Police Progress – Police Station 1F Holding Cells and Morgue
   
7. A. Grace Personal Info – Police Station 2F
   
8. Status A. Grace Police Progress – Police Station 1F First Floor Offices
   
9. G. Soderberg Personal Info – Police Station 1F First Floor Offices
   
10. G. Soderberg Police Progress – Police Station 1F First Floor Offices
    
11. Map of Killings – Police Station 2F Detective Offices
    
12. Missing Persons Report – Police Station 1F Front Desk and Lobby
    
13. Witness Description of Clothing – Police Station 1F Outside bathroom
    
14. Suspect Released – Police Station 1F Front Desk and Lobby
    
15. Killer’s Profile – Police Station 2F
    
16. Spray-Painted Graffiti - Cemetery Silent Shores
    
17. Tabloid Article #1 - Asylum Entrance
    
18. Tabloid Article #2 - Asylum Women's Ward
    
19. News Article #5 - Asylum Women's Ward High Security by Room 217
    
20. News Article #6 - Asylum Entrance upstairs
    
21. Tabloid Article #3 - Asylum Entrance
    
22. K. Douglas Cause of Death – Salem I16 by Cemetery gate
    
23. K. Douglas Family Photo – Salem I16 by Cemetery gate
    
24. C. Nelson Cause of Death - Salem Ghost Playground
    
25. C. Nelson Family Photo – Salem I11 behind the Coffee house
    
26. A. Grace Cause of Death – Salem Ghost Playground
    
27. A. Grace Publicity Photo – Salem Ghost Playground
    
28. G. Soderberg Family Photo – Salem M13 behind the ghost rowboat
    
29. Chalk Bell Symbol – Salem B13 by Asylum entrance
    
30. Baxter’s Official Comment – Salem D3 outside Police Station parking lot
    
31. News Article #2 – Salem Big Playground
    
32. News Article #3 – Salem E15
    
33. News Article #4 – Salem C11
    
34. Witness View of Eyes – Salem O15 Beach
    
35. Witness Trauma Report – Salem Map A13/#6 by Asylum entrance
    
36. Poem 1 – Judgment House 2F Balcony
    
37. Poem 2 – Judgment House 2F Piano room
    
38. Poem 3 – Judgment House 2F Hallway
    
39. Poem 4 – Judgment House 2F Ruined library

Julia's Thoughts

1. Lillian and Lillian - 3F Hallway
   
2. Meeting Ronan's Parents - Apartment 4A
   
3. Ronan’s Fedora – Church Nave
   
4. Second Time’s a Charm – Upper Nave
   
5. Can’t Stop Loving Him – Church Nave
   
6. Sanctuary – Church Rectory 2F by the elevators
   
7. Plain Clothes Cop – Police Station 2F R. O'Connor's Office by the copier
   
8. Ronan Gets His Badge – Police Station 2F R. O'Connor's Office
   
9. Ronan’s Trouble with the Law – Police Station 2F R. O'Connor's Office
   
10. Visit to the Station – Police Station 2F Rex Reyes's Office
    
11. Meaning Behind “Cheated Death” - Cemetery Entrance
    
12. New Roses Tattoo - Cemetery Quarantine Building Recovery
    
13. New Justice Tattoo - Cemetery Quarantine Building
    
14. Why Ronan Became a Cop - Cemetery Silent Shores
    
15. Rex on Ronan’s Record - Cemetery Monument Hill
    
16. Smokin’ Ronan - Cemetery The Lake
    
17. Reckless Ronan - Cemetery Silent Shores
    
18. A Stroll Through the Graveyard - Cemetery Entrance just after Shoreline Investigation
    
19. Hospital Support - Asylum Women's Ward
    
20. Seeking Advice from Rex - Asylum Sealed Area Operating Theater
    
21. Ronan Meets Rex - Museum 1F Ticket Booth
    
22. Museum Date - Museum 1F East Wing Storage Room
    
23. Meaning of Dollar Tattoo – Salem A4 behind gas station (need Teleport)
    
24. That Car Tattoo – Salem S14 outside The Olde Towne Seafood House
    
25. The Day We Met – Salem Big Playground
    
26. Harassed by Baxter – Salem M9 behind Apartments
    
27. Salem Feels Dangerous – Salem M3 outside entrance to Cannon Memorial Park
    
28. Ronan Pops the Question – Salem near the stop sign past 1st Salem Bank
    
29. Our Little Town – Salem I5 narrow area between cannon memorial park sections
    
30. Ronan’s Childhood – Salem L14
    
31. Ronan’s Teens – Salem F15 inside ghost building (need Teleport)
    
32. Family of Three – Salem Ghost Playground
    
33. Escorted by a Knight – Salem D2 Police Station parking lot
    
34. Day at the Beach – Salem R18 Beach Dock
    
35. Life, and After – Judgment House 2F Balcony
    
36. Ronan the Stranger – Judgment House 2F by stairs going down to 1F
    
37. Fight with Ronan – Judgment House 1F
    
38. Pondering the Proposal – Judgment House 1F near Courtroom

Rex's Thoughts

1. Rex’s Sense of Guilt – Salem K11 by the Ghost Gallows
   
2. Rex’s Gratitude – Police Station 2F Rex Reyes's Office

Truth About Baxter

1. Baxter’s Relationship with the Witness’s Mother – Police Station 1F Front Desk and Lobby
   
2. Baxter and Ronan’s Mutual Animosity - Salem M9 behind Apartments

Profiler's Memories

1. Concern for Joy’s Safety - Apartment 4A by the dish rack
   
2. Insights on the Killer’s Motives – Police Station 2F Baxter's Office
   
3. Fear of More Killings - Cemetery Quarantine Ridge
   
4. The Killer’s Delusions - Asylum Entrance
   
5. Museum Spirits – Museum 3F Administration Office
   
6. Sensing Judgment House Disturbances – Judgment House 2F

Ghost Girl's Messages

1. Gallows – Apartments 2F Hallway
   
2. Coffins – Apartments Apartment 3A bedroom
   
3. Dunking Chair – Church Rectory 1F bathroom
   
4. Staircase – Church Rectory 2F
   
5. Demons – Church Attic
   
6. Cannon – Police Station 1F Holding Area
   
7. Judge – Police Station 1F Holding Cells and Morgue
   
8. Sacrifice - Cemetery Silent Shores (need Teleport)
   
9. Ghost - Cemetery Monument Hill
   
10. Twins – Asylum Women's Ward High Security Shower room
    
11. Pillory – Asylum Women's Ward High Security
    
12. Baptism - Asylum Women's Ward Laundry Room
    
13. The Accused - Asylum Sealed Area Room 105
    
14. Mansion - Museum 3F
    
15. Caught - Museum 3F Gallery
    
16. Flowers – Salem N3 Back Alleys 2
    
17. Poppet – Salem B1 behind wooden fence by the Fountain
    
18. Storm – Salem A4 behind gas station (need Teleport)
    
19. Quest – Salem A12 near the Asylum entrance
    
20. In Her Hands – Salem K15 by the big playground
    
21. Burning – Salem L14 by the big playground
    
22. Darkness – Salem M13 behind the ghost rowboat
    
23. Stone – Salem P10 by the ghost boat

GHOST STORIES are the Artifacts that you find in Murdered: Soul Suspect; they don't have a specific number or name so it would be hard to say which is where, that's probably why the Collectible guides doesn't have a section for them

Originally posted by nyiaor:

Salem's History

1. Rectory Dedication Plaque – Church Rectory 1F
   
2. Organ Dedication Plaque – Church Upper Nave
   
3. Burned Rectory Plaque – Church Upper Nave
   
4. 1775 Fortress Plaque – Police Station 1F Front Desk and Lobby
   
5. Forensic Facility Plaque – Police Station 1F Holding Cells and Morgue
   
6. 1777 Battle Plaque – Police Station 1F First Floor Offices
   
7. 1776 Battle Plaque – Police Station 1F Holding Cells and Morgue
   
8. Yellow Fever Memorial Plaque - Cemetery Quarantine Building
   
9. William Pynchon Memorial Plaque - Cemetery Monument Hill
   
10. Graveyard History Plaque - Cemetery The Lake
    
11. Asylum Dedication Plaque - Asylum Entrance
    
12. Spanish Flu Memorial Plaque - Asylum Entrance - upstairs
    
13. Surgical Instruction Theater Dedication Plaque - Asylum Sealed Area
    
14. Train Station Memorial Plaque - Museum West Wing
    
15. Museum Donor Plaque - Museum 3F outside the Break Room
    
16. Dunking a Gossip - Museum 1F West Wing
    
17. Baker in the Stocks - Museum 1F East Wing Storage Room
    
18. Armaments History Plaque – Salem G3 Cannon Memorial Park
    
19. Fountain Dedication Plaque – Salem B2 by the Fountain
    
20. Pirate History Plaque – Salem Q17 Beach
    
21. Gas Station History Plaque – Salem B5
    
22. Ashland Hills Cemetery Plaque – Salem G16 small playground by Cemetery entrance
    
23. Colonial Kitchen Plaque – Judgment House 1F Kitchen
    
24. Colonial Parlor Plaque – Judgment House 1F Courtroom
    
25. Colonial Cellar Plaque – Judgment House Wine Cellar

Witch Trials History

1. Book of Engravings - Museum 3F Gallery
   
2. Prayer Book - Museum Museum 3F Gallery
   
3. Judgment House Plaque – Salem (Map M2/#8)
   
4. Witch Trial History Plaque - Museum 1F Ghost Train
   
5. First Witch Execution Plaque - Museum West Wing Second Floor Stairs
   
6. German Witch Trial - Museum 1F Ticket Booth
   
7. Medieval Witch Book - Museum 3F by elevators
   
8. Witchcraft Superstition Plaque – Museum 1F West Wing Storage
   
9. Judge’s Diary – Judgment House 1F Courtroom

We Finished the Game \o/!! 100% Collectibles!!!

I missed 1 clue in the Cemetery section T_T, all Golden Badges except for the Cemetery (9/10 clues); I think I read something about you being able to start a second playthrough with everything that you unlocked, so you can just focus on what you missed. No, restart just restart EVERYTHING.

Heads up, don't leave the Judgement House 1st Investigation, I saw a collectible just past the wall, it was bait!! the game "progressed" and I couldn't conclude the 1st investigation, I could still go back and look at the clues but I couldn't Resolve the investigation the button prompt disappear! 2 lost Golden Badge!

Finished the game with 100% collectibles and ALL achievements!! \o/!!!