For the second time in 11 days a Prince George's County Circuit Court judge yesterday closed a pretrial hearing to the press and the public in drug-related murder case.

The judge, Audrey E. Melbourne, cited a U.S. Supreme Court decision last year that allowed judges to close hearings held before a trial begins. She had also cited the decision in the New York case of Gannett vs. DePasquale when she closed a pretrial hearing on July 31.

Earlier in the day, Melbourne reversed a previous decision and allowed reporters to observe jury selection.

Melbourne had tentatively decided last Friday that security precautions and overcrowding problems required closing the courtroom. Shortly before the jury selection began yesterday morning, however, she agreed to allow reporters into the packed courtroom.

The defendant, Robert Willie Young, is charged with the 1977 murder of a courier for an alleged $30 million Washington heroin ring. Security for the trial has been described by court officials as the tightest in the last decade in Prince George's County.

The jury selection took most of the day as the judge, prosecutor Thomas Blair, and defense attorney Steven Platt questioned a panel of 90 prospective jurors. The 12 jury members and four alternates are being sequestered in a local motel.

Melbourne said the trial, scheduled to begin today after the swearing in of the jury, is expected to last 10 days to two weeks.