A jail guard was arrested on suspicion of possessing and being under the influence of methamphetamine while on the job at a Southern California lockup, authorities said.

The 42-year-old detentions deputy with the Kern County Sheriff’s Office was taken into custody Tuesday while on duty at the Lerdo Jail Complex near Bakersfield, sheriff’s officials said.

She was not armed at the time of her arrest, officials said.

The deputy, a 21-year veteran of the sheriff’s office, could face charges including entering a jail facility in possession of meth and for being under the influence of a narcotic, KBAK-TV reported Wednesday.