Mayor Marion Barry yesterday announced the creation of a 92-member blue-ribbon D.C. Commission on Crime and Justice to develop programs to reduce the city's spiraling crime rate and unclog the overcrowded court and prison systems.

In a police headquarters press conference, at which Barry had assembled more than half the newly appointed commissioners, the mayor said of the unusually broad-based group: "If it gives us some ideas about how to stop one criminal act, that's better than we're doing now."

The underscore the need for the commission's work, Barry noted that robberies, burglaries and larcenies here have increased 25 percent since 1976, that more than 4,000 adult prisoners are jammed into the city's correctional system and that the U.S. Attorney's office has a backlog of 1,700 felony cases.

Barry, who has all but formally announced he is running for reelection this year against an array of opponents, denied the commission was politically inspired to deflect criticism about the city's growing crime problems.

On the contrary, he told reporters, "We started in March of 1981 with our crime reduction program [with the announcement of a 13-point anticrime campaign by police], and this is just another aspect of that."

The mammoth commission, in the planning stage for more than six months, consists of a wide cross-section of the city's legal, business, labor, religious, academic and civic leaders, as well as two suburban county political leaders, two members of Congress and a scattering of U.S. officials. Barry, who will chair the commission, said its work will last 18 months.

Prince George's County Executive Lawrence J. Hogan and Fairfax County Board of Supervisors Chairman John F. Herrity were both named to the commission, Barry said, because "we need to have a regional approach to solving the crime problem."

One other suburban leader, Montgomery County Executive Charles W. Gilchrist, was asked but declined to join the commission. Barry press secretary Annette Samuels said Gilchrist indicated he did not have enough time to serve on the commission but pledged that Montomery County would cooperate with the group's work.

Members of Congress on the commission are Del. Walter E. Fauntroy (D-D.C.) and Rep. Mervyn M. Dymally (D-Calif.), chairman of the House District judiciary and education subcommittee. Federal officials include Drug Enforcement Administration local chief David Canaday and U.S. Park Police Chief Lynn Herring.

Barry said the commission members will split into six committees assigned to study various aspects of crime reduction and streamlining the criminal justice system. The commission members will work part time and at no cost. Barry said committee staffs will meet weekly and the full committees monthly to recommend specific programs and actions.

Anticrime initiatives in the 13-point program announced last spring have included increasing the size of the 3,660-member police force, use of police decoys and "plants" and encouraging civilian government employes with two-way radios in their cars to alert police to criminal activity.

Executive vice chairman of the new crime commission is Lawrence P. Doss, a partner in the accounting firm of Coopers & Lybrand. Other members range from City Council member David A. Clarke (D-One), D.C. School Supt. Floretta McKenzie and Superior Court Chief Judge H. Carl Moultrie I to Greater Washington Central Labor Council president Robert E. Peterson, gay activist Melvin Boozer, Washington Episcopal Bishop John T. Walker, and former Washington Bullets basketball star Wes Unseld.