An off-duty Gwinnett County police officer is credited with arresting a fitness club manager on theft charges.

Mark Medrano, 35, the manager of LA Fitness Sport Club on Buford Drive in Buford, has been charged with theft by receiving, two counts of criminal attempt to commit crime and possession of tools for commission of crime.

The off-duty officer was working out at the fitness club Friday when he saw Medrano looking through members’ lockers and personal bags and detained him. Stolen personal items were found in Medrano’s possession, as well as a pair of bolt cutters.

He is being held without bond at the Gwinnett County Detention Center.

Police also found a machine used to clone credit cards, credit cards, driver’s licenses and personal belongings of other victims in a search of Medrano’s Lawrenceville home.

The investigation continues and Medrano could face additional charges.