A second citywide unit, the tactical patrol force, patrolled high-crime neighborhoods in the evening and could be mobilized for demonstrations as well.

These citywide units were gradually disbanded.

Inspector O'Boyle, who is 51 years old, operated the citywide anti-crime unit out of one of the new TNT precincts, the 23d.

Since the corruption scandals uncovered by the Knapp commission in the 1970's, those activities have been left primarily to specialized citywide units lest the beat cops fall prey to bribes.

Outside experts said the personnel shuffle was necessary to redirect responsibility for crime fighting and prevention away from citywide and borough-wide units and place them squarely with precinct commanders.

Mr. Biderman said the housing agency would set up a citywide unit to "focus exclusively on eviction actions against suspected drug dealers."

Psychiatric units citywide are overcrowded, the report found, noting that "Harlem and Kings County operate in especially decrepit space."

Using the broadest definition of an S.R.O. unit, a study done for the city in 1993 found that there were 46,700 such units citywide.

The officers, who are assigned to a citywide street-crime unit, were taken to local hospitals.

Using citywide and precinct units, the Police Department first flooded the zone with plainclothes officers and detectives.