WHOEVER THOUGHT up the idea of giving convicted criminals jobs in the police department certainly must be having second thoughts today. This misguided placement, which was not cleared with department officials or the police personnel affected, makes about as much sense as asking a convicted bank robber to guard the city payroll funds, or a heroin dealer to work as a teacher's aide in a high school.

A year ago, the city embarked on a new program to create public jobs for inmates who would not be eligible for parole without employment. Initially, some questions were raised about the equity of giving city jobs to convicted felons when so many young people with no criminal record are out of work. But when it was made clear that only temporary and minimum wage positions were involved, opposition was diminished, particularly in light of the severe problem of prison overcrowding that the jobs program was designed to alleviate. Last April some of the parolees walked off these jobs demanding better pay, health coverage, sick leave and work rules to exempt them from outdoor activities in rain or snow. But the city came down hard, revoking some paroles and adopting a firm "job or jail" policy, and since then the program appeared to be working smoothly.

Now we learn that a monumental error in judgment has been made by the city's Department of Administrative Services, which placed 15 parolees in cleaning jobs inside the police department. The police, who were not told of the identity of these workers, are justifiably furious that their security has been compromised, their informants and undercover men identified and their activities monitored by convicted felons. To make matters worse, at least three parolees with long records involving serious offenses, were working in the 4th District station during the planning of Operation Caribbean Cruise, the largest drug raid ever undertaken by city police. The operation failed apparently because advance notice had been given to the suspects.

The Police Department has now ended its participation in the jobs program, but a thorough review is still in order. Have parolees been placed in other sensitive positions on the city payroll? Have supervisors -- at the very least -- been notified when parolees are sent to fill job slots? Is anyone at a high level in city government reviewing each of these placements on a regular basis?