The Polk County Sheriff's Office is warning the public that devices known as skimmers have been found recently in the Bartow, Mulberry and Haines City areas.

Skimmers are device readers that criminals put on ATMs or other card readers (such as those on gas pumps) that customers use to swipe their debit or credit cards.

Sheriff's detectives and Bartow police are investigating fraud complaints related to skimming devices they say were placed on Publix ATMs in Bartow and Mulberry and on Mid-Florida Credit Union ATMs in Bartow and Haines City.

Skimmers are almost always accompanied by tiny cameras that record the customer entering his/her PIN number after swiping the card. Law enforcement agencies work with business owners to examine their card readers and see if skimmers have been placed within them.

A well-trained eye or physical inspection of the device is key to locating a skimmer, detectives say.

“Our best resource for catching criminals like these is you – the public," Polk County Sheriff Grady Judd said.