CHICAGO, Illinois (AP) -- A 75-year-old woman is suspected of using her age and apparent frailty to fleece about a dozen auto dealers, police and prosecutors said.

Over the past four years, Betty A. Gooch has walked into several Chicago-area dealerships with a cane and an oxygen cart, then paid for cars with bad checks, police said.

"She'll say she's sick and going to be hospitalized, or that her stockbroker is sending the money, or promises they'll have the money next Friday," said Tony Kotlarz, an investigator for the McHenry County state's attorney's office.

In the latest case, Gooch wrote a check for $36,534 for a new Toyota Sienna and another check for $20,041 for a new Toyota Matrix during a November visit to one dealership, said Cook County state's attorney's spokeswoman Marcy Jensen.