D.C. Police Chief Maurice T. Turner Jr. has ordered that all sergeants and officers who work on street patrols in the city wear bulletproof vests, rescinding a September 1984 order that made wearing the vests voluntary, a police spokesman said yesterday.

Turner declined to comment on why he issued the new order Wednesday. Police officials believe the change was prompted by an incident a week ago in which a plainclothes officer who was making a drug arrest was shot in the leg and abdomen by two other plainclothes officers who failed to recognize him as a colleague.

The wounded officer, Ricky Graham, was not wearing a vest.

The deaths of two police officers in 1982 sparked a massive campaign by the department, community groups and the Fraternal Order of Police that ultimately raised $634,000 for the purchase of vests for officers.

However, many officers complained that the 3 1/2-pound vests were too restrictive and uncomfortable -- especially in the summer, when some officers complained that the vests cause heat fatigue and rashes -- and Turner agreed to make wearing the vests optional.

Ron Robertson, executive steward of the FOP, said yesterday: "We're still of the opinion it should be up to the individual officers whether or not to wear a vest . . . . We will probably talk to [Turner], especially when the warmer weather comes," about modifying his order making vests mandatory.