OAKLAND - After four weary months of deliberations, the jury in Oakland's police corruption trial on Tuesday acquitted three former officers of eight counts including kidnapping and assault and said they were hopelessly deadlocked on 27 other charges.

"All avenues have been exhausted," the jurors said in a note read by Alameda County Superior Court Judge Leo Dorado, who soon after declared a mistrial on the remaining charges.

District Attorney Tom Orloff said he was disappointed, but had not decided whether to retry the former beat cops on the unresolved counts. Federal prosecutors said they were reviewing whether they might help revive the case.

An Oakland Police Department spokeswoman reported no increase in problems on city streets following news of the verdict.

The former officers, who called themselves the "Riders" and worked the night shift in one of Oakland's roughest areas, were charged with beating suspects, wrongfully accusing them of crimes, planting drugs and covering it all up by falsifying police reports.

Attorneys for the three - Clarence "Chuck" Mabanag, Jude Siapno and Matthew Hornung - had denied all wrongdoing and pleaded for an end to what they called the longest criminal trial deliberations in California history.

Testimony in the trial began more than a year ago, and the seven-man, five-woman jury began deliberating May 29 when the judge gave them 122 pages of instructions on the 35 counts.

Authorities believe their alleged ringleader, Officer Frank Vazquez, fled to Mexico to escape prosecution.

The four were first fingered by a rookie officer, Keith Batt, who said he was shocked by their alleged conduct. The defendants claimed that Batt, now a police officer in the nearby suburb of Pleasanton, accused them so he could quit with honor.

Defense lawyers had argued their clients were under immense pressure to reduce crime and were simply doing the bidding of a new regime that demanded they wrestle the streets back from criminals.

"I think they wanted scapegoats," said Bill Rapoport, who represented Siapno.

The case outraged a city where police have been unable to curb a rising murder rate. Despite Tuesday's verdicts, the case has created extensive fallout.

In February, the city agreed to pay nearly $11 million and implement police reforms to settle civil rights lawsuits brought by more than 100 people. Last year, prosecutors dismissed about 90 mostly drug-related criminal cases with connections to accused officers.

John Burris, an attorney who represented dozens of alleged victims in the civil lawsuits, said he had prepared his clients for this verdict.

"In this case, the officers were able to argue Oakland is a tough town, and that many of the victims had prior convictions," Burris said. "The argument was to attack the victim and to demonstrate they had backgrounds and these officers did not personally gain from the misconduct and that they were following orders."

He said he was hopeful the department would be reformed and that a court-appointed monitor from the civil case would catch any lapses among street officers.

Some in Oakland took a dimmer view.

"I'm disappointed that they were acquitted, very disappointed," said resident Carrie McGathon. "The message is, 'If you wear the badge, you can get away with something."'

Beleaguered jurors didn't respond to reporters' questions as they left the courthouse.

On Tuesday, they found Siapno innocent of kidnapping and beating; Mabanag innocent of presenting three false claims; and all three officers innocent of conspiring to falsely arrest a suspect.

Oakland Police Chief Richard Word said jurors were "clearly troubled by the evidence" and stood by his decision to fire the officers.

Kevin V. Ryan, the U.S. attorney for Northern District of California, said in a statement that federal prosecutors had monitored the lengthy trial and remained interested in the case.

"We intend to analyze the evidence, consult with the district attorney and the civil rights division of the Justice Department and make a determination about whether there is sufficient evidence to bring a federal civil rights prosecution," Ryan said.

The jury emerged from deliberations Sept. 18 to tell Dorado they could only agree on eight counts and no amount of additional time would produce more verdicts. But the judge exhorted them to try again and returned them to the jury room.

On Tuesday, Dorado conceded the trial was over and thanked jurors.

"The court finds no reasonable probability that the jury can agree" on the remaining counts, given the complexity of the case and the jurors' failure to reach more verdicts during protracted deliberations, Dorado said.

The first of 84 witnesses began testifying on Sept. 18, 2002 and the last one finished nearly seven months later.