Tanned from a week-long vacation in the Bahamas, Richard Lee Earman, the 36-year-old former real estate salesman who has pleaded guilty to conspiring to murder an Arlington couple, went to jail yesterday to await sentencing.

By previous agreement between Arlington Commonwealth's Attorney William S. Burroughs and Earman's own attorney, LeRoy T. Batchelor, Earman appeared before Circuit Court Judge Charles S. Russell, who revoked his $2,000 bond. Earman then surrendered to sheriff's deputies who took him to the county jail.

Earman's incarceration was delayed -- giving him time for the vacation -- as part of a plea bargaining agreement negotiated March 1. Another part of the agreement will permit Earman to serve his sentence in the federal prisor. of his choice. He could be sentenced to as long as 10 years in prison.

Earman made his guilty plea in the deaths of real estate agent Alan Foreman, 26, and Foreman's fiance Donna Shoemaker, 25, who were found shot to death in the garage of Foreman's North Arlington home in April 1977.

Later that year Earman was acquitted of murder charges in their deaths.

As part of the plea bargain that led to his guilty plea to the conspiracy charge, Earman agreed to testify against Joseph N. Martin, 28, of Las Vegas, who is charged with conspiring with Earman to kill Foreman and Shoemaker in order to collect on an insurance policy.

Earman told a reporter yesterday, "I thought aout whether to change my plea every night down there on vacation. But I think the best thing for me is to do my time and get it over with."