KTVK-TV reports (http://bit.ly/1kc1lA6) that 36-year-old Stephanie Carol Evans is accused of stealing a purse from a shopper inside a Wal-Mart store around 7 p.m. Friday.
Police say the female victim chased Evans and wrestled her purse back.
The Arizona Department of Public Safety later spotted Evans' red pickup truck on Loop 202 near McKellips Road.
Authorities say that is when Evans drove as fast as 120 mph to elude officers.
They say Evans then stopped at a Target store and she and her son ran inside.
Police arrested Evans but the boy was able to go home with his father.