One of two defendants charged with operating a cocaine-distribution ring on Capitol Hill was released from jail yesterday after his parents posted his bond.

Douglas Marshall, 27, was released after his parents, Mara and Sylvan Marshall, pledged their $418,000 home in Northwest Washington and posted a $50,000 surety bond to obtain his release.

Marshall was indicted last November along with Troy M. Todd, 27, on charges of operating a cocaine-distribution ring. The arrest of both men a year ago sparked investigations by the Justice Department and the House Ethics Committee into alleged drug use by members of Congress or their staffs on Capitol Hill.

Marshall and Todd left the country in May before their indictment. They were arrested in January in Australia, where they had been living under false identities, and were extradited from there last week.

Marshall had been held in the D.C. jail since Sunday. Todd is also in the jail and will have a hearing on a request for reduction of his bond this morning.

Sylvan Marshall said yesterday his son will begin working Monday for the International Gem and Mineral Show Inc., a Bethesda company that arranges gem shows. He also said he is looking forward to his son, a law school graduate, passing the bar examination.

On Wednesday the elder Marshall urged U.S. District Court Judge Thomas F. Hogan to "accept the plea of a devoted father and mother" and reduce their son's bond so that he would not have to remain imprisoned pending his trial.