Terrence G. Johnson, the Prince George's County youth convicted of slaying a county police officer in 1978, returned to court yesterday to ask that his conviction be overturned because of a previously undisclosed conversation between the presiding judge and a juror in the highly publicized case.

Johnson's attorneys argued that their client was denied his constitutional right to be present at all phases of the March 1979 trial when Circult Court Judge Jacob Levin met with juror Jacqueline Ball to discuss a complaint she had about the jury foreman -- that she felt him to be prejudiced.

Johnson attorney R. Kenneth Mundy told Circuit Court Judge Howard Chasanow Levin committed a "reversible error" by holding the private conversation with Ball and not telling Johnson's attorneys or Johnson afterward the substance of the conversation. Because of that, Mundy said, Chasanow should overturn Johnson's conviction and order a new trial.

Johnson was charged in 1978 with murdering two county police officers. After an emotional trial, the then 16-year-old was acquitted of the murder charges but found guilty of two lesser offenses -- manslaughter in the case of one officer and illegal use of a handgun. The jury found Johnson innocent by reason of insanity in the death of the other policeman.

Johnson, who was tried and sentenced as an adult, is serving a 25-year term at Patuxent Institute in Jessup, Md. His attorneys have exhausted appeals at various state courts and recently asked the Supreme Court to consider the case.

At yesterday's post-conviction hearing, which Johnson's attorneys requested, Mundy and colleague Allen Lenchek made the unusual move of putting Judge Levin on the stand to testify about his meeting with juror Ball.

Levin said he received a note or some other form of communication from Ball during the trial asking to speak to him. He said he told lawyers for both sides -- but not Johnson -- he would meet with Ball, see what she wanted and get back to them if it was necessary.

Levin said he met Ball in his chambers and she told him she felt foreman William Burns was prejudiced because he had told her he felt the black jurors were sticking together. Race became a dominant element of the trial and publicity surrounding it because of a history of tension between the county's black community and its mostly white police force. Johnson is black and the two officers -- Albert M. Clagget IV and James Brian Swart -- were white. Both Ball and foreman Burns are white. Levin testified he felt Ball had come to him with a personality conflict and that "I thought I had solved the problem" by speaking with her.

Prince George's County State's Attorney Arthur A. Marshall Jr., who prosecuted the original case against Johnson, said yesterday the issues raised by Johnson's defense and the post-conviction hearing were merely "housekeeping matters." As a result, he said, he does not expect the conviction to be overturned or a new trial ordered.

The issue of the conversation between Levin and Ball was minor, he said, and Johnson's attorneys should have found out what happened since they had known about it and informed their client.

Johnson attorney Lenchek said he expects Chasanow to render a decision in mid-January and added he does not expect the issue to be over at that time. i