A 58-year-old man has been convicted in a federal drug and sex trafficking case for prostituting women in the District and in Maryland and using the Internet to advertise, according to federal prosecutors.

Kenneth Wayne Hart, also known as “Big Daddy” and “Bill Red Hart,” among other monikers, was convicted Thursday by a jury after a seven-day trial in U.S. District Court in Greenbelt, federal prosecutors said.

Hart, who lives in Beltsville in Prince George’s County, was found guilty of possession with intent to distribute drugs and witness tampering. He was also found guilty of conspiracy to engage in sex trafficking along with sex trafficking by force, fraud and coercion.

The U.S. attorney’s office for the District of Maryland said that from December 2016 through April 2017, Hart and a co-conspirator ran a prostitution business that recruited women to engage in sex acts. Prosecutors said Hart supplied the women with heroin and crack cocaine and threatened to withhold drugs “if the victims displayed any sign of disobedience or tried to leave the locations where the commercial sex acts occurred.”

Authorities said the women were forced to turn over identification cards, credit cards, cash, clothing, phones and earnings. Prosecutors also said Hart used violence to enforce his rules. Investigators included officials from the FBI and Prince George’s County police.

Hart is to be sentenced July 8.