Officials demonstrated one well-played tactic that involves three offenders- the stall.
"Victim goes to the revolving door. He is stalled by the offender in front of him. Wallet is taken and passed off to a third offender," Sgt. Michael Jones said.
Those fumbling with smartphones are particularly vulnerable, police say.
"He is going to be delayed by someone coming out of the door. Offender comes up behind him, lifts his wallet, passes it off," Sgt. Jones said. "We've got three offenders here."
Officers say they're on the lookout for 165 known pickpockets who work Chicago's busy shopping streets.
"This is their thing. They wake up in the morning, and they think, 'Who is going to be their victim today?'" Commander John Graeber said.
One of those pickpockets is convicted felon Chris Brown, police say. He was caught by CTA surveillance cameras digging the wallet out of the front pocket of a man who thought he was doing a good deed. But, it ends up Brown's accomplice was just pretending his foot was stuck on a train platform, police say.
Brown has 117 pickpocketing arrests.
"Most of these people who are pickpockets people think they are younger but they are 30, 40, 50 years old. They work in groups of three, four people," Commander John Graeber said.
Police say Good Samaritans are good targets for pickpockets, including those who help with directions. The best thing shoppers can do, police say, is remain aware of their surroundings.
"I keep my purse cross body and my cellphone accessible," Lindsay Leone said.
"You know you need to be aware while shopping downtown," Celeste Sullivan said. "Yeah, I was just thinking I need to zip my purse."