Investigators said store security at the store in Ocala, Fla., about 40 miles south of Gainesville, confronted sisters Allison Niemeyer, 19, and Laura Niemeyer as they tried to leave with $57 in stolen clothes stuffed into a diaper bag and a DVD player.
Allison Niemeyer bolted, leaving her 1-year-old son behind. Her sister also managed to get away.
"When the loss prevention officer asked her, 'Are you going to come get your child?' she said, 'It's not my child. It's not my child.' And she continued to leave, and then they both abandoned the baby," said Ocala Police Sgt. Chas Maier.
Police caught up with the sisters the next night at a dance club and arrested them.
The sisters were charged with felony child neglect and theft. The mother was on probation for a home invasion robbery committed while she was pregnant.
The boy was placed in protective custody.