NEW YORK, JULY 20 -- The state of New York today faulted senior police officials and New York City Mayor David N. Dinkins (D) for failing to prepare for and adequately respond to the three days of racial violence in the Crown Heights neighborhood of Brooklyn two years ago.

A 600-page report from the state's commissioner of criminal justice detailed numerous instances of breakdowns in communication between police at the scene of the rioting and top brass, mishandling of 911 calls and inexplicable delays in moving to quell violence.

"Major mistakes were made," said Richard Girgenti, director of criminal justice and the principal author of the report. "There were both individual and systemic failures."

But the report found no evidence to support what had been the most incendiary contention in the aftermath of the rioting -- that Dinkins had restrained the police from taking aggressive action during the first two days of the rioting. It was this rumor that had led some Jewish leaders to accuse Dinkins of antisemitism.

Instead, the document blamed a "collective failure" by top-ranking police officials -- including then Commissioner Lee P. Brown, now the federal drug policy director -- for consistently underestimating the extent of the violence. Dinkins, it said, relied uncritically on the analysis of police officials, ignoring contradictory evidence from the news media and community leaders.

The criticism of Dinkins was strong enough that some political analysts said they believe the report could have a major impact on this fall's mayoral contest between Dinkins and Republican candidate Rudolph W. Giuliani.

"The swing voters never believed that Dinkins was an antisemite," said Jay Severin, a political commentator and consultant in Manhattan. "That's not the issue for them. They want to know whether he's a competent manager. . . . This report validates the essential claim of the Giuliani campaign, that Dinkins isn't competent."

At a news conference today, Dinkins said: "This report concludes my reliance {on the police} was misplaced. I accept that conclusion. I wish I had challenged the police account earlier." But Dinkins vowed that "What happened at Crown Heights will never again happen," and he said that he hoped "the truth in this report will serve to speed the healing."

In a statement released today in Washington, Brown said he takes "full responsibility" for actions taken during his tenure and added that "hindsight is 20/20."

The Crown Heights disturbances began on the evening of Aug. 19, 1991, after a 7-year-old black child, Gavin Cato, was struck and killed by a car driven by a member of the Crown Heights Hasidic community. The accident, and a subsequent false rumor that a Jewish-run ambulance on the scene ignored the fatally injured boy, ignited long-standing tensions between the black, largely West Indian inhabitants of the neighborhood and the 15,000 members of the Lubbavitcher sect who have lived in Crown Heights since the end of World War II.

Gangs of black youths began roaming the neighborhood, throwing bottles and rocks. Late in the evening, a 29-year-old rabbinical scholar, Yankel Rosenbaum, was fatally stabbed. The report said the investigation of Rosenbaum's death was bungled.

One of the most chilling sections of the report is the reprinting of transcripts of emergency calls to 911 from Hasidic Jews in the midst of the rioting.

911 operator: Police operator. . . . Where is your emergency?

Caller: Yes, it's President Street. My name is {deleted}. They have just come in through the door and they're attacking my wife. . . . They're storming through the windows -- they're breaking the windows.

911 operator: How many people broke into your house?

Caller: I have a gang out here. . . . Would you please hurry up?

For the first two days of the violence, however, the New York police followed a policy of restraint, staying close to fixed command posts and often declining to stop or intervene in acts of violence and looting. The report said police believed "that aggressive tactics would only exacerbate an already tense situation."

The report said, however, that the police were far too slow to change this strategy when it became clear that it wasn't working. The report also appears to treat with disbelief Dinkins's contention that he was not aware that the riot was out of control until Wednesday -- two days after all the New York newspapers and television stations had published articles or shown live footage of looting and rock-throwing, and after a sniper had wounded eight police officers.