| Det. Frank Arcaro? (138 episodes 1958-1963) | Harry Bellaver | |
| Narrator (1958-1963)? (138 episodes 1958-1963) | Lawrence Dobkin
 | |
| Lt. Michael 'Mike' Parker? (113 episodes 1958-1963) | Horace McMahon
 | |
| Det. Adam Flint? (99 episodes 1960-1963) | Paul Burke
 | |
| Libby Kingston (49 episodes 1960-1963) | Nancy Malone
 | |
| Det. James 'Jimmy' Halloran (39 episodes 1958-1959) | 詹姆斯·弗朗西斯
 | |
| Lt.. Dan Muldoon? (26 episodes 1958-1959) | 约翰·麦克因泰
 | |
| Desk Sergeant? (18 episodes 1958-1963) | James Little | |
| Police Surgeon? (13 episodes 1959-1962) | Robert Dryden | |
| Detective Dutton? (10 episodes 1958-1961) | Richard Kronold | |
| Doc Nearing? (9 episodes 1958-1963) | House Jameson | |
| Janet Halloran (9 episodes 1958-1959) | Suzanne Storrs | |
| Detective? (8 episodes 1961-1963) | Sorrell Booke
 | |
| Freddie - Lab Man? (8 episodes 1961-1962) | William Cottrell | |
| Prisoner? (7 episodes 1959-1962) | Robert Weil | |
| Alfy Tiloff? (6 episodes 1959-1963) | 杰克·克鲁格曼
 | |
| Barney Peters? (6 episodes 1959-1963) | Nehemiah Persoff
 | |
| Al Buxley? (6 episodes 1960-1963) | Roger C. Carmel | |
