A couple from Mesa, Arizona, was arrested for allegedly stealing thousands of dollars worth of library books and reselling some of them to a local bookstore, according to police.

Ian Bartlett, 36, and Athena Bartlett, 33, checked out $6,200 worth of unreturned library books from Mesa Public Library under two different accounts and resold hundreds of them, the Mesa Police Department said.

The couple was arrested on Monday at Mesa Public Library after library staff observed the pair in the library and notified the police, police said.

Ian Bartlett and Athena Bartlett were both booked on charges of theft, a class four felony, and trafficking stolen property, a class two felony.

Police had launched an investigation into the incident following a report on Tuesday, May 19, from Mesa Public Library that a male and female had attempted to sell numerous books with library labels still attached to a local secondhand bookstore, police said. Bookstore employees advised the pair they were not able to purchase the library books, after which the two left the business, according to authorities.

After the bookstore shared the incident with Mesa Public Library, library staff determined the books had been checked out by Ian Bartlett, whose library account had been blocked after approximately $1,565 worth of books were not returned, according to police.

Investigators discovered that a second library account was opened under Ian Bartlett’s name, which had 66 outstanding books, 19 of which were recovered at the bookstore, according to police.

Investigators learned that Athena Bartlett had completed five transactions at the bookstore involving 423 books between Thursday, May 7 and Thursday, May 14, authorities said.

Detectives are continuing to investigate the incident. Authorities said they believe there are still numerous unrecovered Mesa Public Library books involved in the case.

Anyone who believes they unknowingly purchased a stolen Mesa Public Library book or has one of the stolen books is encouraged to contact the Mesa Police Department so detectives can determine which books were involved in the incident.