A 24-year-old Northwest Washington man was convicted yesterday of first degree murder for strangling a 27-year-old Langley Park woman while robbing her apartment.

Robert Carway Clark of 12th Place NW also was convicted of armed robbery. He was an acquaintance of the woman, Millicent Mouzon-Johnson, an employe of the National Labor Relations Board and a 1975 graduate of George Washington University.

According to testimony in Prince George's County Circuit Court, Clark and a friend -- who also was an acquaintance of the victim -- decided to burglarize Mouzon-Johnson's apartment as they were driving home from a party on May 9, about an hour before the murder.

Clark testified that the idea to burglarize the apartment and kill Mouzon-Johnson came from his friend, Arthur Ross. He told the jury that as they drove to the victim's apartment, Ross said, "If she's there, we tie her up and kill her." Clark said he disagreed with the plan but that Ross said it would be necessary to kill Mouzon-Johnson to keep her from identifying them.

Ross is charged with first degree murder in the case and will go to trial in January. He has pleaded not guilty.

Mouzon-Johnson's body was discovered less than one hour after the murder by her father, Ralph Mouzon, a retired guidance counselor for McFarland Junior High School in Northwest Washington.

Mouzon testified that he had driven to his daughter's apartment to give her a ride to the post office. When she was not outside the building waiting for him, as was her custom, he knocked on her apartment door. Finding it unlocked, he entered and found his daughter dead on a mattress on the bedroom floor.

A lamp cord was around her neck and wrists and her feet were bound with a sheet. Her body was still warm, Mouzon testified, so he tried to give her artificial respiration.

Public defender Darlene Perry argued that Clark did not actually kill Mouzon-Johnson, although he stole her stereo and was in her apartment with Arthur Ross on the morning she was killed.

Assistant state's attorney Bond Rhue argued that Clark had helped murder the victim and was guilty of first degree murder as an accomplice. Rhue requested a life sentence for Clark.