A D.C. Superior Court judge yesterday dropped his apparently unprecedented plan to re-impanel a jury that had been dismissed and complete a murder trial that another judge already had ruled was a mistrial.

Judge Eugence N. Hamilton said in a brief "response" he filed with the D.C. Court of Appeals that he would not go forward with the case. On Tuesday, at the request of federal prosecutors, the appeals court had ordered Hamilton not to implement his plan pending further rulings to be issued by that court after Hamilton had replied to the government's request.

Court officials said yesterday that Hamilton would set a date for a new trial for the three defendants. They are a new trial for the three defendants. They are charged with second-degree murder in the slashing and stabbing death of James Marshman, 39, a construction worker, in front of a bar and grill at 9th and L Streets NW on the night of Oct. 10, 1975.

Defense attorneys have said they intend to challenge any retrial of their clients on the grounds that this would place them in "double jeopardy" - being tried twice for the same offense - in violation of the U.S. Constitution.

Their argument has been that there was no justification for ruling a mistrial in the first place. The mistrial was ordered last Thursday by Superior Court Judge Nicholas S. Nunzio. Nunzio said at the time that he was making the ruling because two of the three court appointed defense counsel had performed ineffectively.

In hearings before Hamilton Monday, federal prosecutors contended that Nunzio had been justified. They also said Judge Hamilton had no authority to overrule Nunzio and no authority to reconvene the jurt. They said they would litigate the "double jeopardy" issue in the Court of Appeals if necessary.

Under the law here, a defendant is in "jeopardy" once a jury is sworn in his trial. But if actions by the defense subsequently cause a mistrial, a second trial of the case would not constitute double jeopardy.