"They're targeting people that are older, people that are maybe less aware, or more friendly," said Naperville Police Commander Michaus Williams.
Police say the suspects engaged the victims in a conversation, and then switched out their valuable jewelry with low-cost jewelry.
"I don’t know how they do it!" said Nada, a shopper outside Fresh Market. "I mean, it’s crazy!"
The incidents occurred in the afternoon of May 30, June 3, and June 6 at the Route 59 Costco, the Ogden Avenue H Mart, and the 75th Street Fresh Market.
Police warns residents to be careful if a stranger approaches, and to report any suspicious activity to 911.
"Keep them at a good distance. Don't approach their vehicles. If somebody is summoning you, just say I'm good, keep walking or engage them in a conversation from afar," said Commander Williams.
Authorities estimate that $10,000 worth of jewelry was stolen in just the three incidents. The crimes were not violent, no injuries were reported, and the victims were both male and female.
Naperville police are working with other police departments in the area to see if theft is going on anywhere else.
Call Naperville police if you’ve witnessed a crime, or you have been a victim of something similar.