A Scotland Yard ballistics expert is called into identify a murderer through a scientific analysis of the bullet that killed a man.
| Actor | Role |
|---|---|
 Edgar LustgartenSelf - Narrative By | Self - Narrative By |
| RRobert ChurchillSelf - and Featuring | Self - and Featuring |
 Robert RaglanInspector Dexter | Inspector Dexter |
| JJohn StuartLocal Inspector | Local Inspector |
| JJohn WarwickJohn Patterson | John Patterson |
| CChristine AdrianEmily Thatcher | Emily Thatcher |
 Alastair HunterSandy - Gamekeeper | Sandy - Gamekeeper |
 Anthony BateAmbulance Man | Ambulance Man |
 Walter GotellPolice Constable (uncredited) | Police Constable (uncredited) |
| HHoward LangDavy Charlesworth | Davy Charlesworth |
| BBen WilliamsJim Grundy - Poacher | Jim Grundy - Poacher |
| JJohn RaePathologist | Pathologist |
| PPhilip DalePolice Sergeant | Police Sergeant |
| SSimon LackJulie's Friend at Fairground (uncredited) | Julie's Friend at Fairground (uncredited) |
 Shay GormanReporter (uncredited) | Reporter (uncredited) |
| PPat Hagan3rd Man Leaving Inquest (uncredited) | 3rd Man Leaving Inquest (uncredited) |