Most D.C. government and public school employees whose jobs entail direct contact with children will have to undergo criminal background checks no matter when they were first hired, under new rules published Friday.

The emergency regulations issued by the Department of Human Resources will take effect in 30 days and could affect as many as 15,000 city workers. They require that each current employee or unsupervised volunteer in a covered position “be subjected to an initial criminal background check” within 45 days of the rules’ implementation, and then to submit to periodic checks at least every two years.