WikiLeaks founder Julian Assange stands on the balcony of the Ecuadorean Embassy in London in February 2016. (Frank Augstein/AP)

Federal prosecutors are weighing whether to bring criminal charges against members of the WikiLeaks organization, taking a second look at a 2010 leak of diplomatic cables and military documents and investigating whether the group bears criminal responsibility for the more recent revelation of sensitive CIA cyber-tools, according to people familiar with the case.

The Justice Department under President Barack Obama decided not to charge WikiLeaks for revealing some of the government’s most sensitive secrets — concluding that doing so would be akin to prosecuting a news organization for publishing classified information. Justice Department leadership under President Trump, though, has indicated to prosecutors that it is open to taking another look at the case, which the Obama administration did not formally close.

It is not clear whether prosecutors are also looking at WikiLeaks’ role last year in publishing emails from the Democratic National Committee and the account of Hillary Clinton campaign chairman John D. Podesta, which U.S. officials have said were hacked by the Russian government. Officials have said individuals “one step” removed from the Kremlin passed the stolen messages to WikiLeaks as part of a broader Russian plot to influence the 2016 presidential election.

Prosecutors in recent weeks have been drafting a memo that contemplates charges against members of the WikiLeaks organization, possibly including conspiracy, theft of government property or violating the Espionage Act, officials said. The memo, though, is not complete, and any charges against members of WikiLeaks, including founder Julian Assange, would need approval from the highest levels of the Justice Department.

Barry J. Pollack, an attorney for Assange, said Justice Department officials had not discussed with him or Assange the status of any investigation, despite his requests that they do so. He said there was “no legitimate basis for the Department of Justice to treat WikiLeaks differently than it treats other journalists.”

“The fact of the matter is — however frustrating it might be to whoever looks bad when information is published — WikiLeaks is a publisher, and they are publishing truthful information that is in the public’s interest,” Pollack said. “Democracy thrives because there are independent journalists reporting on what it is that the government is doing.”

Pollack noted that the Obama administration was “no shrinking violet when it came to pursuing reporters and journalists,” a reference to the Obama Justice Department’s repeated attempts to prosecute leakers. Pollack said he hoped “this administration will be more respectful, not less respectful, of the First Amendment than the prior administration was.”

Prosecutors are trying to determine the extent to which WikiLeaks encouraged or directed sources to engage in illegal activity.

In March, WikiLeaks published thousands of files revealing secret cyber-tools used by the CIA to convert cellphones, televisions and other ordinary devices into implements of espionage. The FBI has made significant progress in the investigation of the leak, narrowing the list of possible suspects, officials said. The officials did not describe WikiLeaks’ exact role in the case beyond publishing the tools.

Prosecutors are also reexamining the leaks from Chelsea Manning, the Army soldier who was convicted in 2013 of revealing sensitive diplomatic cables. Manning chatted with Assange about a technique to crack a password so Manning could log on to a computer anonymously, and that conversation, which came up during Manning’s court-martial, could be used as evidence that WikiLeaks went beyond the role of publisher or journalist.

But journalists routinely employ methods — or tell sources to employ methods — that will help them avoid being identified. Justice Department officials in the previous administration believed that prosecuting Assange or other members of WikiLeaks could open the door to prosecuting news organizations and journalists who published classified information, and so they opted instead to target people, such as Manning, who had clearances to access such information and gave it to reporters.

“Any prosecution that’s based solely on publishing stolen classified information is going to be very difficult because of the First Amendment problem,” said Michael Vatis, a former Justice Department official who oversaw ­cybercrime investigations and is now a partner at Steptoe & Johnson.

Vatis said Assange’s “exact words would matter a lot.” Just expressing a desire to obtain classified information would not be enough to bring charges, he said.

“I think their only realistic hope is some conspiracy charge based on WikiLeaks’ involvement in the actual hacking, not just publishing the results of the hacking,” Vatis said. “So if they were somehow planning with the hacker to do the hack or planning, in this case, with the contractor to steal the information so that WikiLeaks could publish it, then I think they’d have a much stronger chance of successfully prosecuting them.”

The FBI and the Justice Department declined to comment for this article.

A prosecution of WikiLeaks members would probably draw fierce opposition from ­open-government and free-press organizations that see the group as practicing journalism, even if its brand is unconventional.

Trump has had a fluid relationship with WikiLeaks, depending largely on how the group’s actions benefited or harmed him. On the campaign trail, when WikiLeaks released Podesta’s hacked emails, Trump told a crowd in Pennsylvania, “I love WikiLeaks!” But when it came to the release of the CIA tools, he did not seem so pleased.

“In one case, you’re talking about highly classified information,” Trump said at a news conference earlier this year. “In the other case, you’re talking about John Podesta saying bad things about the boss.”

CIA Director Mike Pompeo said during an appearance at the Center for Strategic and International Studies this month that it was “time to call out WikiLeaks for what it really is: a non-state, hostile intelligence service often abetted by state actors, like Russia,” and he criticized prior administrations as having been “squeamish” about going after publishers of state secrets.

“They have pretended that America’s First Amendment freedoms shield them from justice. They may have believed that, but they are wrong,” said Pompeo, who had touted WikiLeaks’ material on the DNC when he was a congressman.

In a sign of the Justice Department’s seriousness in pursuing charges, the U.S. attorney’s office in the Eastern District of Virginia recently added a veteran prosecutor, Assistant U.S. Attorney James Trump, to the case, officials familiar with the matter said. James Trump, who is also assigned to the case against Edward Snowden, won criminal convictions in 2015 against former CIA officer Jeffrey Sterling, who was charged with leaking classified information to journalist James Risen. Prosecutors in that case initially sought to compel Risen to reveal his source before they ultimately backed down.

Assistant U.S. Attorney Tracy Doherty-McCormick, who examined the case under the Obama administration, also has been working on the matter in recent weeks, officials said.

In a recent Washington Post op-ed piece, Assange said that his group’s motive was “identical to that claimed by the New York Times and The Post — to publish newsworthy content.”

“The media has a long history of speaking truth to power with purloined or leaked material — Jack Anderson’s reporting on the CIA’s enlistment of the Mafia to kill Fidel Castro; the Providence Journal-Bulletin’s release of President Richard Nixon’s stolen tax returns; the New York Times’ publication of the stolen ‘Pentagon Papers’; and The Post’s tenacious reporting of Watergate leaks, to name a few,” Assange wrote. “I hope historians place WikiLeaks’ publications in this pantheon. Yet there are widespread calls to prosecute me.”

He said in a later podcast interview with the Intercept that he believed Justice Department rules barred a prosecution of him. “If they follow those rules, if they follow the First Amendment, they shouldn’t be pursuing a prosecution,” he said.

Prosecutors would also face practical hurdles in reviving the case involving Manning. Years have passed, and witnesses’ memories are likely to have faded. Prosecutors also fear that Manning might not be a cooperative witness and that defense attorneys might raise questions about her credibility, officials familiar with the case said.

Manning had been sentenced to 35 years in prison, but Obama commuted her prison term in the waning days of his administration.

Asked Thursday about his concern about leaks and whether it was a priority for the Justice Department to arrest Assange, Attorney General Jeff Sessions said, “We are going to step up our effort and already are stepping up our efforts on all leaks.” He added, “Whenever a case can be made, we will seek to put some people in jail.”

Rachel Weiner contributed to this report.