In the same year of 1896, Detective Wooldridge, disguising himself
as a cheap thief, entered a Clark street criminals' resort and
fraternized with thieves, murderers and vagabonds of all kinds, in
order to obtain information, leading Wooldridge into the most amazing
school of crime ever witnessed by a Chicago police officer. He was
accepted in good faith as a proper sneak thief by the brotherhood,
and for his benefit the "manager" of the den put his "pupils" through
their "lessons."
These lessons were in shoplifting, pocket picking, purse snatching
and other forms of larceny requiring skill and deftness. When he had
seen enough Wooldridge generously volunteered to "rush the growler"
and went out--and called the patrol wagon. Twenty-three crooks were
arrested this time. Each one of them swore he would have killed the
detective had his makeup or conduct for an instant directed suspicion
toward him.