One of the first challenges to Maryland's eight-month-old death penalty law failed yesterday when a Prince George's County circuit court judge ruled that the man accused of raping and murdering a 13-year-old Annapolis girl last summer could be sentenced to death if found guilty.

Judge Howard S. Chasanow ruled that William Joseph Parker, 28, who is accused of killing 13-year-old Elizabeth Archard last Aug. 28, could be sentenced to death under the law passed by the state legislature last year.

Chasanow turned down arguments by Parker's lawyer, Fred Bennett, that the new law, which went into effect last July 1, was unconstitutional.

Under Maryland law, after a defendant is found guilty of first-degree murder, either the trial jury or the judge must determine whether to impose the death penalty. In making this decision, the law requires that the judge or the jury balance any mitigating circumstances against a specifically defined set of possible "aggravating circumstances."

Bennett contended yesterday that even if only one mitigating circumstance is proved, the defendant should not suffer the death penalty. Those are the provisions of the death penalty statute in Texas, a law that was upheld by the U.S. Supreme Court.

"The Maryland law adds another step," Bennett said. "The defendant must not only prove that a mitigating circumstance exists but that it outweighs the aggravating circumstance."

Chasanow, however, agreed with prosecutor Edmund O'Connell's arguments that the law was constitutional. The law concerning the jury's consideration of mitigating circumstances is "one step divided into two," Chasanow said, and not two steps as Bennett argued.

After making his ruling on the state death penalty, Chasanow granted Bennett's request that the trial be moved from Prince George's County to st. Mary's County in southern Maryland, because of prejudical pretrial publicity in the Washington area.

If conviceted and sentenced to death, Parker could become the first man to die in Maryland's gas chamber since 1961.