Richard Tichnell, 32, convicted of murdering a western Maryland sheriff's deputy, yesterday became the first person to be sentenced to die under Maryland's 14-month-old death penalty law.

Judge Richard Pollitt deliberated about four hours in Wicomico Circuit Court on the Eastern Shore before sentencing Tichnell to Maryland's gas chamber for fatally shooting the deputy following a robbery. A jury convicted Tichnell of the slaying earlier this week.

"The court believes," the judge said, "that under the findings of the jury and the findings of the court . . . that if it's going to follow the law it has but one course to take. Despite the anguished hours, we have a duty to perform," United Press International reported.

The last execution in Maryland was carried out at the State Penitentiary in Baltimore in 1961.

Under the state's new death penalty law, there is an automatic appeal of any death sentence to the Maryland Court of Appeals.

A 1972 Supreme Court decision voided death penalty laws in the country, but subsequent court rulings have held that the death penalty is constitutional under certain circumstances. Maryland passed its new law last year.

Tichnell was found guilty of murdering Garrett County Deputy David G. Livengood, who was attempting to arrest Tichnell and a companion after the robbery of an Army-Navy surplus store in Oakland in western Maryland last January. The trial was moved to the Eastern Shore at the request of the defense.

Tichnell admitted that he killed Livengood, but argued that he shot in self-defense after the deputy shot him in the shoulder, according to Wicomico County State's Attorney Richard Warren. Livengood was shot eight times, according to Warren.

Following a first-degree murger conviction, either the judge or the jury holds a special hearing to determine whether the death penalty should be imposed. Tichnell decided yesterday to allow Pollitt to decide his fate.

The judge ruled that the "aggravating circumstances" in the case -- the fact that the victim was a police officer killed while Tichnell was trying to evade capture -- outweighed "mitigating circumstances."

Tichnell's attorney argued there were eight such circumstances, but Pollitt ruled that only one was valid -- that Tichnell had no record of criminal violence.