With a sharp rebuke, a federal judge on Thursday rejected Exxon's attempt to shut down two state investigations into whether the oil giant misled investors for years about the risks of climate change.

U.S. District Court Judge Valerie Caproni dismissed Exxon's complaint with prejudice, meaning the company can't refile it.

In the first line of her ruling, the judge describe Exxon's actions as "running roughshod over the adage that the best defense is a good offense."

"The relief requested by Exxon in this case is extraordinary: Exxon has asked two federal courts—first in Texas, now in New York—to stop state officials from conducting duly-authorized investigations into potential fraud," she wrote. "It has done so on the basis of extremely thin allegations and speculative inferences."

Caproni dismissed Exxon's claim that Attorneys General Maura Healey of Massachusetts, Eric Schneiderman of New York, and others had launched a conspiracy to deprive the company of its First Amendment rights and silence its views on climate change.

Exxon claimed the plot roped in activists, lawyers and philanthropies and culminated when the group AGs United for Clean Power held a press conference in 2016.

Exxon's key evidence for this theory involved statements made at that press conference, and was the result of "cherry-picking snippets" from the transcript, the judge said.

"Nothing that was said can fairly be read to constitute declaration of a political vendetta against Exxon," Caproni wrote.

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Exxon's allegations that the attorneys general "are pursuing bad faith investigations in order to violate Exxon's constitutional rights are implausible," the judge wrote. And she said that it was "a wild stretch of logic" for Exxon to contend that Healey's and Schneiderman's tone and comments about public confusion related to climate change showed any intent to "chill dissenting speech."

"The American people deserve answers from Exxon, and we will get them," Healey, the Massachusetts attorney general, wrote on Twitter in announcing the ruling. Schneiderman, too, said his probe would continue.

Exxon spokesman Scott Silvestri told Reuters the company was evaluating its legal options. "We believe the risk of climate change is real and we want to be part of the solution," he added.

Investigators and Investigative Reporting

Healy and Schneiderman had announced their investigations into Exxon following the publication of an investigative series of stories in InsideClimate News and later the Los Angeles Times that disclosed Exxon long understood the consequences of global warming but engaged in a campaign to cast doubt on the scientific conclusions.

The judge rejected Exxon's arguments that the news articles, which were based on decades of internal company documents as well as interviews and historical sources, were used as a pretext by the attorneys general.

"The only basis for Exxon's allegation that these articles are a pretext is that, according to Exxon, the documents cited in the articles 'demonstrate that [Exxon]'s climate research contained myriad uncertainties and was aligned with the research of scientists at leading institutions at the time'," she wrote.

"Assuming the truth of Exxon's characterization of the documents, they appear to support the AGs' legal theory that Exxon's internal research was consistent with the scientific consensus but that Exxon made statements to the market and the public that suggested otherwise. In any event, Exxon has included no factual allegations that tend to show that the AGs do not believe that the articles based on Exxon's documents have raised legitimate concerns that should be run to ground," the judge wrote.

Did Exxon Mislead Investors on Climate Change?

The two investigations focused on those very concerns: whether past statements by Exxon questioning climate change science and downplaying its risks to the company constituted a form of fraud against the public and its shareholders.

At first, Exxon complied with New York's demands, providing more than a million documents. But it filed suit in federal court in Texas in June 2016 against Healey, and later added Schneiderman.

In Texas, the company found a judge sympathetic to its arguments. In a 2016 ruling that appeared to turn the tables by allowing the investigated to become the investigators, U.S. District Court Judge Ed Kinkeade, in Texas, ordered Healey and Schneiderman to appear for depositions under questioning by Exxon lawyers.

Kinkeade justified the order by saying he thought Healey, especially, had acted in bad faith when opening the Exxon investigating.

The two attorneys general argued Exxon lacked jurisdiction to fight the case in the Texas court because it was the improper to sue them outside of their jurisdictions. Kinkeade finally relented and ordered the case transferred to New York while at the same time signaling his support of Exxon's arguments.

Caproni's ruling on Thursday dismissed the federal case, but Exxon and the two attorneys general remain locked in legal combat in New York and Massachusetts state courts.

Exxon's bid to block Healey's investigation in the state courts has been sent to the Massachusetts Supreme Judicial Court, the last stop on legal path there. A ruling could come as soon as May.

The case in New York continues its legal journey, which has produced disclosures that former Exxon CEO and later Secretary of State Rex Tillerson used a shadow email account under the alias "Wayne Tracker," and allegations that the company used one set of numbers in describing greenhouse gas risks to investors but used a secret set internally.

"Exxon has run a scorched earth campaign to avoid answering our basic questions about the company's awareness of climate change," Healey said in a statement on Thursday. "Massachusetts customers and investors deserve answers from Exxon about what it has known about the impact of burning fossil fuels on its business and the planet, and whether it hid this information from the public."