 Stanley BakerDetective Sergeant Jack Truman | Detective Sergeant Jack Truman |
 Anne HeywoodCathie Murphy | Cathie Murphy |
 David McCallumJohnnie Murphy | Johnnie Murphy |
 Peter CushingFather Laidlaw | Father Laidlaw |
 John SlaterSgt. Walker | Sgt. Walker |
 Clifford EvansHeadmaster Evans | Headmaster Evans |
 Moultrie KelsallSuperintendent | Superintendent |
 George A. CooperChief Inspector | Chief Inspector |
| BBrona BolandMary Murphy | Mary Murphy |
| FFergal BolandPatrick Murphy | Patrick Murphy |
 Michael ChowAlexander | Alexander |
 Tsai ChinPrimrose | Primrose |
 Sean LynchSlick | Slick |
| BBernice SwansonMeg | Meg |
 Freddie StarrTommy | Tommy |
 Sheila RaynorMrs. Catlin | Mrs. Catlin |
| CChristopher CookeDavid Catlin | David Catlin |
| IIrene ArnoldMrs. Baker | Mrs. Baker |
| OOonagh QuinnJilly Baker | Jilly Baker |
| AAli AllenBoy (uncredited) | Boy (uncredited) |
 Grace ArnoldCustomer in Grocer's Shop (uncredited) | Customer in Grocer's Shop (uncredited) |
| JJohn BoxerPolice Sergeant (uncredited) | Police Sergeant (uncredited) |
 Jeremy BullochPageboy at Hotel (uncredited) | Pageboy at Hotel (uncredited) |
| JJohn Bush(uncredited) | (uncredited) |
| MMichael CollinsPolice Officer in Patrol Car (uncredited) | Police Officer in Patrol Car (uncredited) |
| KKeith CraneWilliam (uncredited) | William (uncredited) |
| GGerrard Gibson(uncredited) | (uncredited) |
| VVictoria HarringtonChild (uncredited) | Child (uncredited) |
 Melvyn HayesKid in Johnnie's Gang (uncredited) | Kid in Johnnie's Gang (uncredited) |
| LLindsay HooperPolice Sergeant (uncredited) | Police Sergeant (uncredited) |
