The case against Richard Lee Earman, the accused killer of an Arlington real estate salesman and his finance, went to the jury yesterday after both prosecution and defense attorneys presented their final arguments.

Earman is accused of murdering Alan W. Foreman, 26, and his finance, Donna Shoemaker, 25, who were found shot to death last May 8 in Foreman's yellow Jajuar in the garage of his home at 1201 N. George Mason Dr. in Arlington.

In his closing argument to the jury yesterday, Arlington County Commonwealth's Attorney William S. Burroughs admitted that the evidence against Earman, who did not testify in his own behalf, had come before the jury in a "jumbled manner." One of the most confusing factors in the trial, Burroughs said in his summation, was the prosecution's original contention that former New York Life Insurance salesman Joseph N. Martin "was part of the plan to kill Foreman."

The prosecution's theory began to change, Burroughs said, when an Arlington County jail inmate, Larry Piper, testified that Earman told him that "the underlying motive" for Foreman's murder was "a cocaine ripoff involving Mafia figures."

Earman, Burroughs contended, acted as an "assassin" who was hired to commit the murder by organized crime figures from whom Foreman had borrowed money in a drug deal. When Foreman didn't pay the money back. Burroughs said, Foreman was killed in order that his creditors might collect on his $56,000 life insurance policy.

After confronting Martin with piper's testimony, Burroughs argued Martin admitted that he had received an anonymous, threatening note the day that Foreman's and Shoemaker's bodies were discovered. Martin was told not to divulge "any names." Martin also said that Earman had told he owed money in a cocaine deal to a "loan shark named McGowan" whom Burroughs described as "an organized crime figure."

Charges against Martin were then dropped last work. Burroughs reminded the jury, after Martin passed a lie cetector test. Instead of being responsible for the killings. Martin "was used as Silcox was used," an innocent victim of a still unexplained drug deal, Burroughs said. Charles Silcox, a Northern Virginia manager for the Door Stores, Inc., had also been indicted in connection with the murders until Burroughs dropped charges against him last month for lack of evidence.

Earman's attorney, John K. Zwerling, described the case against his client as "garbage," and attacked both the plausibility of Burrough's speculations as well as the credibility of the prosecution's witnesses.

Zwering contended that he himself had first mentioned the name McGowan to Earman and that Earman passed the name on to Martin only as part of the discussion in which both Earman and Martin were speculating as to who had killed Foreman.

In addition, Zwerling described Burroughs' three main witnesses as a "trio" that included "a jailhouse Mental hospital, according to evidence snitch, a sociopath and The Thorazine Kid." Piper had been described by several fellow inmates as a "jailhouse snitch," while Ronnie John James, another inmate who said Earman had confessed the murders to him, was taking Thorazine, a major tranquilizer, at the time the alleged confession took place.

In addition, Ray Tugwell Jr., a convicted burglar who testified that Earman offered him $5,000 to commit the murders, was diagnosed 10 years ago as a sociopath by a Virginia State Mental hospital, according evidence introduced in the trial. "I can't prove a person's lying," Zwerling said. "I can't make Pinnochio's nose grow. But I submit to you that he (Tugwell) is a pathological lair."