Four people are facing numerous charges that they delivered drugs to the Richmond City Jail.

Sheriff C.T. Woody Jr. announced Monday that four Richmond residents were arrested after being indicted on 42 felony charges for bringing heroin and other drugs to the jail.

Woody said the investigation is ongoing and more arrests may be made.

The investigation began in November when sheriff’s deputies uncovered an attempt by one of the suspects to deliver heroin to the jail. The investigation came to a close last month, and the suspects were indicted on Wednesday.

Woody said his office is doing its best to “stem the tide of narcotics trafficking” into the jail, which jeopardizes the safety of both inmates and staff.