IT COMES full circle in an awful way: Mary Treadwell, convicted five years ago of conspiring to defraud the federal government and low-income tenants -- that is the terrible crime of taking money meant for the poor -- has been given a job on the city government payroll as a $27,748-a-year expert on women offenders. It seems that the administration of Mayor Marion Barry is, in the words of Gladys W. Mack, head of the D.C. Parole Board, "interested in her" and wants "to take advantage of her firsthand experience to do something about the problems faced by women offenders." Taxpayers, too, have been "interested in her" ever since the 1960s, when she and Mr. Barry, who was her husband, were running the now-defunct Youth Pride job training program. Mr. Barry was not implicated in the investigation of her real estate venture that grew out of Youth Pride, but Mary Treadwell spent 18 months in federal prison for her crime.

Mrs. Mack correctly points out that the new employee has "paid her debt to society" -- but is that enough reason for society, in the form of government, to start paying her for questionably useful work after what she did to government? Or might there not be a little something out there in the private sector that would be more suitable?

In any of these situations, it is not merely conflicts of interest that should be considered, but the appearance of possible conflicts that may be perceived by citizens whose taxes pay the salaries. So far, Mary Treadwell's contribution is a report on the needs of women offenders during incarceration and after their release -- which, according to a number of experts in this field, covers no new ground.

So the whole thing doesn't sit well, at a time when public confidence in local government needs every encouragement it can get. Rehabilitation of criminals is one thing; returning one to the environment, if not the scene of the crime, with a vague but publicly underwritten job is poor policy.