Patricia Roberts Harris stood yesterday outside a small Northeast Washington grocery store that was burglarized four times in recent years and, in the first major issues statement of her campaign for mayor, declared that the D.C. government "is losing the war on crime."

Harris, considered the leading challenger to Mayor Marion Barry for the Democratic nomination, proposed to set up three new agencies and councils to crack down on repeat criminal offenders, to assist the victims of crimes and to help merchants and residents protect themselves.

She said the cost of most of her initiatives would be negligible and that she has no plans to increase city spending to hire additional police officers. The key to combating crime is through better management of existing manpower, she said, and this would be done in part by deploying more foot patrols than Barry has authorized.

With a small cluster of perspiring campaign aides and reporters looking on, Harris labeled the 62 percent increase in violent crimes here during the last three years a "disgrace and a tragedy."

Crime in the city is disproportionately high, she said, and she blamed Barry for not doing more to deal with the problem.

"There is no general, no commander-in-chief coordinating the anticrime activities of this city," Harris said. "Pat Harris as mayor will move to win the war on crime by putting into place devices and programs to make sure there is swift, firm and fair administration of justice."

In response to a question, Harris also said that the emergency bail reform and pretrial detention legislation supported by Barry and approved by the D.C. City Council this week was "essentially irrelevant" to the fight against crime.

The bill will allow prosecutors to hold some defendants in jail longer before bringing them to trial and allow more time to investigate possible violations of probation or bail conditions by persons arrested for new crimes who have already been convicted of or are awaiting trial for other alleged crimes.

Harris said that even with changes in the pretrial detention law, to strengthen the hand of the courts and the U.S. attorney's office in dealing with repeat offenders, the law probably wouldn't be used in more than 100 cases a year.

"The new emergency statute gives the impression of movement without any change in our ability to deal with the reality of the problem," Harris said.

Harris told reporters she selected Carl's Grocery, 2102 Rhode Island Ave. NE, as the site of her press conference because the store was part of a small business district that has been directly affected by rising crime.

"This place represents the reality of the fact that the District of Columbia is losing the war on crime," she said.

Paul Trescott, a coowner of the store who said he isn't supporting Harris' candidacy, said he generally was pleased with the D.C. police department's recent efforts to protect businessmen in his area from break-ins and holdups.

"In this neighborhood, they've been very active in trying to stop crime," Trescott said.

D.C. Police Chief Maurice T. Turner said yesterday that Harris's accusation that the city was losing the war on crime was "invalid" and overlooks progess made this year in stabilizing or reducing crime.

During the first five months of this year, there were a total of 6,402 burglaries and 3,845 robberies, compared to 6,554 burglaries and 3,968 robberies the first five months of 1981, according to police statistics.

"I'm very optimistic that crimes committed in calendar 1982 will be lower than crimes committed in 1981," Turner said.

Turner said some of Harris's proposals for reducing crime, including creating a Mayor's Crime Control Council to coordinate activities of federal and local criminal justice officials, were "warmed over" ideas.

Harris said that members of the proposed council, including representatives of the U.S. attorney's office, the corrections system, the D.C. corporation counsel, the police, public defender and pretrial release services, would meet regularly to exchange information and discuss ways to speed up the disposition of cases involving dangerous offenders and to increase the rate of convictions.

Turner said that he already meets regularly with many of those officials to discuss criminal justice problems.

Harris also would create a Victim Support Services Division within the D.C. Department of Human Resources to provide victims with emergency social services and legal and medical aid and counseling. Staff for that program would be stationed in every police precinct.

And Harris proposed to create a community anticrime assistance corporation to help businesses and community groups who want to get involved in crime prevention measures.

She said she would put her program in place within weeks of taking office in January.

Harris said her proposals would break new ground and would not duplicate efforts by Barry, who issued a 13-point crime program of his own in February 1981.

Lea Adams, Barry's campaign press secretary, said yesterday that the mayor "welcomes suggestions from all sources" regarding ways to reduce and prevent crime.

"He Barry is delighted that Mrs. Harris has focused on an issue on which he as mayor has taken action for the last 3 1/2 years of his administration," she said.