Richard Lee Earman, the central figure in one of Northern Virginia's most controversial murder cases, was sentenced yesterday to 10 years in prison for conspiring to murder an Arlington man for a promise of $15,000.

Earman, dressed in a three-piece navy blue suit, stood silently as Arlington Circuit Court Judge Charles S. Russell told him he had "no alternative" but to impose the maximum sentence on him during a five minute court hearing.

"I'll make no further comment about the background of this case," Russell said, noting that the cases has been "extensively covered in other proceedings."

Earman, clean-cut, 37-year-old former real estate salesman, publicly has confessed that he killed both Alan Foreman and Foreman's finance, Donna Shoemaker, two years ago in return for the promise of $15,000 from Joseph N. Martin, a life insurance salesman. Martin, convicted last week of murder for hire and second-degree murder in the deaths, faces a possible life prison sentence for his role in the 1977 killings.

Under Virginia law, Earman, however, will be eligible for parole in about 2 1/2 years, accordng to Arlington prosecutor William S. Burroughs Jr., whose handling of the murder cases was a key issue in his defeat for reelection Nov. 6.

A presentence report recommends that because of the brutal nature of the killings Earman be considered ineligible for parole. Burroughs said yesterday he doubts that Earman will be parole when he is first eligible.

If Russell accepts a jury's sentence of life imprisonment for Martin on Jan. 18, authorities say he could be eligible for parole after serving 20 years.

Burrough's politcal opponent, Republican-endorsed lawyer Henry E. Hudson, accused Burroughs of bungling the case against Earman during a 1977 murder trial. Earman then was aquitted of murdering the couple but earlier this year he pleaded guilty to a charge of conspiring to kill Foreman. eUnder a controversial plea agreement, Virginia authorities have agreed to let Earman serve his sentence in a federal prison.

Burroughs defended the agreement insisting it was essential to resolving the Foreman-Shoemaker murders, described by police as one of the most brutal killings in Arlington history.

Earman was a key witness against Martin and at a court hearing last spring Earman testified that the execution-style slaying "didn't bother" him. In a presentence report prepared by a Virginia probation officer Earman was quoted as saying that the murders had "eaten at him."

Probation officer William J. Lavelle said in that report that "in light of the fact that [Earman] made four separate attempts to kill [Foreman] . . . his claims for an attack of conscience seem questionable."

The report also said that Earman, a convicted member of the Washington "Beltway Bandits gang" has committed "at least 500 burglaries" in is lifetime.

Earman this year admitted to committing more than 200 burglaries in Fairfax County since his 1977 acquital on murder charges. Fairfax detectives say that those cases represent the majority of unsolved burglaries in the county.

Earman's prison will be chosen in the next few months according to the availability of beds and after state and federal officials classify him according to the severity of his crime and past criminal record.

Burroughs, who did not stop Earman from taking a week's vacation in the Bahamas last winter after he pleaded guilty, also agreed to drop other criminal charges against Earman that grew out of the killings. The charges included attempted murder for hire, use of a sawed-off shotgun in an attempted on Foreman's life a week before his slaying and twice burglarizing Foreman's home the night of the murders.

Last month during Martin's trial Earman testified that he shot Foreman and Shoemaker in the head at point-blank range after the three had returned from an evening at Tramps, a Georgetown disco. In a matter-of-fact voice Earman testified that he returned to Foreman's garage twice after shooting the couple, once firing more bullets into the couples' faces to make certain they were dead.

Police said they could not prosecute Earman for the Fairfax break-ins because they had no independent evidence to link him to the crimes.