A D.C. police officer's involvement in five alleged brutality cases, the first occurring in August 1986 and the fifth last weekend, has sparked debate about how the city handles complaints against police officers.

Central to the issue is the Civilian Complaint Review Board, a seven-member commission that serves as a court of inquiry for police officers accused of brutality, harassment or use of bad language.

Police officials said the board serves the significant function of giving people a public forum to redress problems with police, but expressed concerns that the delays, in some cases years long, result in unfair treatment of officers.

Community leaders question why Officer Wayne Walker, a two-year member on the force against whom four brutality complaints had been lodged in 14 months, is still patrolling the streets.

Walker is being investigated on allegations by two men that he beat them during their arrests in Adams-Morgan last weekend.

The board, created in 1982, receives more than 350 complaints a year, but is laboring under an extensive backlog, outmoded equipment, little funding and few staff members, according to Alfreda Davis Porter, the commission's executive director.

One-third of the complaints filed are dismissed as unfounded, she said.

Porter, who has been in her position eight days, said Mayor Marion Barry's highest priority for the review board is to identify why there is such a backlog.

"It is a problem of great concern and has to be dealt with aggressively," she said.

Efforts are being made now to modernize the department, with an annual budget of about $343,000 and a staff of 10.

Porter said is it not unusual for officers to have several complaints filed against them. But she said she hopes to start notifying police officials as soon as an officer begins to have repeated complaints.

"It might be an early warning signal to problems," she said. "It would provide officers with more of a support structure."

Last weekend in the 2400 block of 18th Street NW, Walker was transporting a prisoner to the 3rd District station when 20-year-old Fernando Luna approached him for help, according to witnesses. They said Luna was beaten without provocation and arrested by the officer, as was 33-year-old Linwood Bentley, who objected to Luna's treatment during the arrest.

Hispanic community leaders, concerned about the latest incident, met with 3rd District officials Thursday to discuss Walker's actions. However, officials said they could not comment on the incident during their investigation.

In the complaints filed with the review board, Walker is accused of:Beating up the Rev. Alvin Ferrell of Landover on Sept. 13, 1986, after Ferrell stopped to ask officers if two men they were arresting were injured and needed help. Ferrell has since filed a $5 million civil lawsuit against Walker and the city.

Beating Lance Jerry Gaines of 1320 Corcoran St. NW near his home on Feb. 26. Another complaint was filed by Gaines' sister, but was dismissed by the board because she did not witness the incident.

Attacking Grady Harris of 87 Melrose St. after Harris' car broke down on Sept. 13 near K Street and Vermont Avenue NW.

Slamming Afshin Moalem, of Beltsville, into the asphalt and breaking his wrist on Sept. 19.

Walker told his union representative yesterday that he had not been informed by the board of the complaints, said Chief Shop Steward David Israel, of the Fraternal Order of Police.

Union officials also expressed concern over the length of time the board takes to process the complaints. This week, for example, Police Chief Maurice T. Turner Jr. received a recommendation from the board to terminate an officer for a complaint that was filed against the officer on July 18, 1983, according to police sources.

Union officials said the board has become a tool for disgruntled people to get back at officers who arrested them. "A lot of these complaints are prejudiced complaints, because if you locked somebody up it's a perfect way to get back at the officer," Israel said.