UPPER MARLBORO, Md. – Parents with children at Thomas Johnson Middle School recently received a startling lesson about the educational practice known as “passing the trash” that’s putting students at risk of sexual assault.

An NBC Washington investigation into Thomas Johnson assistant principal Zelvin Staten revealed he was accused of sexually abusing a third grade student at his previous job as a teacher in Virginia’s Arlington County school district in 2006.

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“According to state education records obtained under the Freedom of Information Act, a September 2013 investigation by Arlington County Child Protective Services found … the abuse occurred inside a classroom closet and continued in successive years when the girl was in the fourth and fifth grades,” the news site reports.

“Police investigated Staten but said (they) didn’t have evidence to recommend criminal charges. Staten was not prosecuted. The records show he has denied the accusations from the outset.”

The girl alleged Staten forced her to perform oral sex.

But Arlington County Child Protective Services allegedly violated the law by failing to inform the school district or the state of the results of its investigation and Staten resigned from Claremont Elementary in 2013 without mention of the investigation in his employment record.

The situation allowed him to find a new job a few weeks later as assistant principal of Thomas Johnson Middle School, where he worked until he again resigned in January 2017.

The failure of Arlington County Child Protective Services to notify the proper authorities, as required by law, prevented state officials from revoking Staten’s teaching licenses until May 2017, NBC Washington reports.

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“That’s the type of mistake you never want to make,” child sex abuse counselor Eliana Gil told the news site. “It’s a very serious mistake and a very grave situation that puts kids at risk.”

It’s also a situation that’s repeatedly played out in school districts across the country. Educators accused of sexually abusing students are often allowed to resign from their position – many times with a letter of recommendation negotiated by their teachers union – with no mention of their educator sexual misconduct investigation.

The predators then secure employment in another school district, where they often repeat their gruesome behavior with new victims.

The “passing the trash” problem has reached epidemic proportions in recent years, and in 2015 Congress mandated that states must adopt regulations to outlaw the shady deals. So far, six states have approved legislation specifically addressing the “passing the trash” problem, while others have passed lesser measures to increase reporting requirements for school employees, volunteers and contractors.

Washington, Oregon, Missouri, Pennsylvania, Connecticut, and Nevada now outlaw the secret deals, while Massachusetts and New Jersey lawmakers are currently considering the same, according to EnoughAbuse.org.

In most states, there is no law against the union-negotiated separation agreements.

Currently, the nonprofit “Stop Educator Sexual Abuse, Misconduct & Exploitation” (SESAME) is advocating for other states to follow through on the federal mandate, president Terri Miller told EAGnews.

“We’re working to make sure states know they have this mandate hanging over their head,” she said.

In the meantime, parents are left to wonder whether their children are safe at school.

“They could have notified me of a potential danger to my child,” Dwight Francis, father of one of Staten’s students at Thomas Johnson. “She’s in the seventh grade and he was a seventh-grade adviser.”