A former Muskegon County postal employee pleaded guilty Friday to a federal charge of unlawfully opening mail culled from her route last May.

Samantha Rose Gentz came under scrutiny after special agents from the USPS Office of Inspector General began getting complaints about packages disappearing from her routes, court records show. She was hired in June, 2014.

In May, 2015 a test envelope addressed to ‘Jerri Tomlin’ containing a transmitter was placed in her carrier case, federal court records show.

“Gentz unlawfully opened the test envelope, along with approximately 15 other letters entrusted to her,’’ federal prosecutors wrote.

She was indicted in January on two counts of unlawfully opening mail, which is punishable by up to five years in prison and a $250,000 fine.

As part of a plea deal, the government will not prosecute Gentz’s theft in 2014-15 of mail packages containing approximately 360 units of hydrocodone, according to a plea agreement. Hydrocodone is an opioid pain medication.

Gentz remains free on a $5,000 unsecured bond. A sentencing date has not been set.