Duplicate lists will also be left with all pawnbrokers with the request that they notify the police if anyone offers to pledge any of the stolen articles.
Other detectives will drop casually into places suspected as being "fences," and closely question the proprietors as to what new articles he has purchased recently.

Of course, the "fence" gives little or no information, but he thereby lays himself open to prosecution as a receiver of stolen goods should they be found on his premises subsequently.
Next, Manning starts in operation his most potent machinery for the apprehension of minor criminals.

He is aware that about ninety per cent.
of his detectives have little or no detective ability.

They are known as "stool pigeon" men, and it probably would be no exaggeration to say that they comprise ninety-five or ninety-eight per cent.

of the entire active detective force.