PHOENIX — A Republican-backed review of the 2020 presidential election in Arizona’s largest county ended Friday without producing proof to support former President Donald Trump’s false claims of a stolen election.

After six months of searching for evidence of fraud, the firm hired by Republican lawmakers issued a report that experts described as riddled with errors, bias and flawed methodology. Still, even that partisan review came up with a vote tally that would not have altered the outcome, finding that Biden won by 360 more votes than the official results certified last year.

The finding was an embarrassing end to a widely criticized, and at times bizarre, quest to prove allegations that election officials and courts have rejected. It has no bearing on the final, certified results. Previous reviews of the 2.1 million ballots by nonpartisan professionals that followed state law have found no significant problem with the vote count in Maricopa County, home to Phoenix. Biden won the county by 45,000 votes, key to his 10,500-vote win of Arizona.

For many critics the conclusions, presented at a hearing Friday by the firm Cyber Ninjas, underscored the dangerous futility of the exercise, which has helped fuel skepticism about the validity of the 2020 election and spawned copycat audits nationwide.

“We haven’t learned anything new,” said Matt Masterson, a top U.S. election security official in the Trump administration. “What we have learned from all this is that the Ninjas were paid millions of dollars, politicians raised millions of dollars and Americans’ trust in democracy is lower.”

Cyber Ninjas acknowledged in its report that there were “no substantial differences” between the group’s hand count of ballots and the official count. But the report also made a series of other disputed claims the auditors say should cast doubt on the accuracy and warrant more investigation.

Trump issued statements Friday falsely claiming the review found widespread fraud. He urged Arizona Attorney General Mark Brnovich, a Republican vying for his party’s U.S. Senate nomination, to open an investigation.

Brnovich, who has been criticized by Trump supporters for not adequately backing the review, did not commit: “I will take all necessary actions that are supported by the evidence and where I have legal authority,” he said in a statement before the report was made public.

Republicans in the state Senate ordered the review under pressure from Trump and his allies, subpoenaing the election records from Maricopa County and selected the inexperienced, pro-Trump auditors. It took months longer than expected and was widely pilloried by experts.

Still, the Arizona review has become a model that Trump supporters are pushing to replicate in other swing states where Biden won. Pennsylvania’s Democratic attorney general sued Thursday to block a GOP-issued subpoena for a wide array of election materials. In Wisconsin, a retired conservative state Supreme Court justice is leading a Republican-ordered investigation into the 2020 election, and this week threatened to subpoena election officials who don’t comply. Backers also called for additional election reviews in Arizona on Friday.

None of the reviews can change Biden’s victory, which was certified by officials in each of the swing states he won and by Congress on Jan. 6 — after Trump’s supporters, fueled by the same false charges that generated the audits, stormed the U.S. Capitol to try to prevent certification of his loss.

The Arizona report claims a number of shortcomings in election procedures and suggested the final tally still could not be relied upon. Several were challenged by election experts, while members of the Republican-led county Board of Supervisors, which oversees elections, disputed claims on Twitter.

“Unfortunately, the report is also littered with errors & faulty conclusions about how Maricopa County conducted the 2020 General Election,” county officials tweeted.

Election officials say that’s because the review team is biased, ignored the detailed vote-counting procedures in Arizona law and had no experience in the complex field of election audits.

Two of the report’s recommendations stood out because they showed its authors misunderstood election procedures — that there should be paper ballot backups and that voting machines should not be connected to the internet. All Maricopa ballots are already paper, with machines only used to tabulate the votes, and those tabulators are not connected to the internet.

The review also checked the names of voters against a commercial database, finding 23,344 reported moving before ballots went out in October. While the review suggests something improper, election officials note that voters like college students, those who own vacation homes or military members can move to temporary locations while still legally voting at the address where they are registered.