Related Clues:

• Sleuth, in slang
• See 20 Across
• Private eye, slangily
• Magnum, e.g., briefly
• Spade, e.g., slangily
• Actor Van Dyke
• Spade, e.g., briefly
• Sherlock
• Van Dyke or Van Patten
• V.I. Warshawski, e.g.
• Dick Tracy is one, briefly
• Detective, slangily
• Sleuth (Sl.)
• Gumshoe, slangily
• Pulp protagonist, perhaps