A D.C. Superior Court judge has ordered reinstatement of a District police officer who was fired 3 1/2 years ago. He also awarded back pay of more than $55,000.

Judge William E. Stewart Jr. ruled that there was insufficient evidence for the police department to fire Denise Wilson who the department charged was "malingering or feigning illness or disability in order to evade the performance of duty."

Wilson, who had been on the force for about four years when she was fired in 1978, was accused by investigators of allegedly climbing into and out of her car "in a normal manner without any evidence of abnormality."

Wilson had suffered inuries to her head, neck and back on May 11, 1976, in an accident while returning to work after a court appearance, according to court papers.

On September 8, 1977 Wilson was notified that she had been charged with malingering. At a trial board hearing in January 1978, she was convicted of the charges and the trial board panel recommended her removal from the force, which was done.

Her attorney, James W. Pressler Jr., appealed the decision on the ground that there was insufficient evidence of malingering. An attorney for the police department said no decision had been made whether the department would appeal the court decision.