- TECS
- Sleuths
- Columbo, Spade, and others
- Private eyes, in slang
- Gumshoes, in slang
- Noir protagonists, often
- Clue finders
- Dicks
- Gumshoes
- Gumshoes, for short
- Investigating cops
- Private eyes
- Sleuths, for short
- Spade and Hammer
- Sleuths, in slang
- Hammett characters
- Paretsky's Warshawski and Grafton's Millhone, briefly
- Private eyes, for short
- 31 Across et al.
- Spade and Marlowe, briefly
- Spade et al., briefly
- Film-noir heroes
- Case workers, briefly
- Sleuths, briefly
- Nero Wolfe and Sam Spade, briefly
- Noir sleuths
- Investigators, slangily
- PI's
- Shamuses
- Professional snoops
- Crime fiction characters
- 23 Across et al.
- Hawkshaws.
- Plain-clothes men: Slang.
- Business records: Abbr.
- Whodunit V.I.P.'s
- Sherlocks, for short
- Soho sleuths
- Barnaby Jones et al.
- British gumshoes
- Lt. Columbo et al.
- Clue hunters, slangily
- Private eyes, slangily
- Hired sleuths, slangily
- Private investigators, for short
- Shadows
- Shadows, briefly
- Hammer or Spade types
- Gumshoes, in old crime fiction
- Slag for sleuths
- People on the case, for short
- They're on the case, in slang
- Gumshoes, informally
- Sleuths, in old slang
- P.I.s, e.g.
- PIs, slangily
- Pulp heroes, often
- Pulp fiction private eyes
