Special Counsel Robert Mueller is using a grand jury in Washington as part of an investigation into potential coordination between the Trump campaign and Russia, a person familiar with the probe said Thursday.

The use of a grand jury, a standard prosecution tool in criminal investigations, suggests that Mueller and his team of investigators are likely to hear from witnesses and demand documents in the coming weeks and months. The person who confirmed to The Associated Press that Mueller had turned to a grand jury was not authorized to discuss the investigation by name and spoke on condition of anonymity.

The Wall Street Journal first reported the use of a grand jury.

Grand juries are common vehicles to subpoena witnesses and records and to present evidence, though they do not suggest any criminal charges are near or will necessarily be sought. It was not immediately clear how or whether the Washington grand jury was connected to the work of a separate one in Alexandria, Virginia. That panel has been used to gather information on Michael Flynn, Trump's former national security adviser.

A spokesman for Mueller's team did not return an email seeking comment.

Mueller's reliance on a grand jury is the "logical next step in this investigation" given that it's the traditional method for prosecutors to gather evidence, said Washington defense lawyer Jacob Frenkel.

Meanwhile, lawyers for President Donald Trump said they were unaware of the existence of a grand jury and had no information to suggest the president himself was under federal investigation.

"With respect to the news of the federal grand jury, I have no reason to believe that the president is under investigation," defense attorney John Dowd told the AP.

Ty Cobb, special counsel to the president, said he wasn't aware Mueller had started using a new grand jury.

"Grand jury matters are typically secret," Cobb said. "The White House favors anything that accelerates the conclusion of his work fairly. ... The White House is committed to fully cooperating with Mr. Mueller."

It was not clear what witnesses might appear before the grand jury or what evidence it might be accumulating or presented with.

Mueller was appointed special counsel in May by the Justice Department following the firing by Trump of FBI Director James Comey. He has since assembled a team of more than a dozen investigators, including current and former Justice Department prosecutors with experience in international bribery, organized crime and financial fraud.

That team has been working at an undisclosed location in Washington, so presenting evidence inside a federal courthouse in the city could be more convenient for the group of investigators than working out of Alexandria. Mueller also worked as a prosecutor in Washington before becoming FBI director, a job he held for 12 years.

A grand jury "increases the power of the prosecutors," said David Levine, law professor at the University of California Hastings College of Law. "Instead of asking for people to provide testimony, they can demand testimony under the penalty of perjury and under risk of contempt of court. And with respect to documents, instead of asking people for documents, they can demand documents. And so for example the tax returns, a subpoena can unlock those tax returns," he said.

News of the grand jury came as senators introduced two bipartisan bills aimed at protecting Mueller from being fired by Trump, with both parties signaling resistance to any White House effort to derail the investigation into Russian meddling in last year's election.

Trump's defense team has been looking into potential conflicts of interest among members of Mueller's team, such as past political contributions to Democrats including Hillary Clinton, and Trump has warned that any effort by Mueller to look into his finances would fall outside the scope of Mueller's appointment.

Under the regulations, Deputy Attorney General Rod Rosenstein is the government official empowered to fire Mueller under limited circumstances, such as conflict of interest and dereliction of duty. Rosenstein, who appointed Mueller, has publicly said he has seen no basis for firing him.

Oakland, California - Aug. 3, 2017

1. David Levine looks at news story on phone

2. Screen showing news story about grand jury in Russia probe

3. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

++ covered by video ++ "What we've learned is that special counsel Mueller and the lawyers working with him ++ are using a grand jury to further their investigation into the questions about Russian collusion and related areas such as financial transactions and other matters."

Washington, D.C. - June 21, 2017

4. AP Photo of former FBI director Robert Mueller arriving for meeting at Capitol Hill

Oakland, California - Aug. 3, 2017

5. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

++ covered by video ++ "It increases the power of the prosecutors. ++ Instead of asking for people to provide testimony, they can demand testimony under the penalty of perjury and under risk of contempt of court. And with respect to documents, instead of asking people for documents, they can demand documents. And so for example the tax returns, a subpoena can unlock those tax returns."

Huntington, West Virginia - Aug. 3, 2017

6. AP Photo of President Donald Trump speaking at rally

Washington, D.C. - Dec. 11, 1998

7. AP Photo of President Bill Clinton walking to Rose Garden to deliver statement on impeachment

Oakland, California - Aug. 3, 2017

8. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

++ covered by video ++ "If it's somebody in the United States, they are subject to subpoena. And that would include the president of the United States. Famously President Bill Clinton appeared before a grand jury. It turned out not very well for him."

Oakland, California - Aug. 3, 2017

9. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"We're probably months and months away before we hear formally ++ covered by video ++ from Mr. Mueller as to whether and who might be indicted and for what." ++

Washington, D.C. - June 21, 2017

10. AP Photo of former FBI director Robert Mueller arriving for meeting at Capitol Hill

Special Counsel Robert Mueller is using a grand jury in Washington as part of an investigation into potential coordination between the Trump campaign and Russia, a person familiar with the probe said Thursday.

The use of a grand jury, a standard prosecution tool in criminal investigations, suggests that Mueller and his team of investigators are likely to hear from witnesses and demand documents in the coming weeks and months. The person who confirmed to The Associated Press that Mueller had turned to a grand jury was not authorized to discuss the investigation by name and spoke on condition of anonymity.

The Wall Street Journal first reported the use of a grand jury.

Grand juries are common vehicles to subpoena witnesses and records and to present evidence, though they do not suggest any criminal charges are near or will necessarily be sought. It was not immediately clear how or whether the Washington grand jury was connected to the work of a separate one in Alexandria, Virginia. That panel has been used to gather information on Michael Flynn, Trump's former national security adviser.

A spokesman for Mueller's team did not return an email seeking comment.

Mueller's reliance on a grand jury is the "logical next step in this investigation" given that it's the traditional method for prosecutors to gather evidence, said Washington defense lawyer Jacob Frenkel.

Meanwhile, lawyers for President Donald Trump said they were unaware of the existence of a grand jury and had no information to suggest the president himself was under federal investigation.

"With respect to the news of the federal grand jury, I have no reason to believe that the president is under investigation," defense attorney John Dowd told the AP.

Ty Cobb, special counsel to the president, said he wasn't aware Mueller had started using a new grand jury.

"Grand jury matters are typically secret," Cobb said. "The White House favors anything that accelerates the conclusion of his work fairly. ... The White House is committed to fully cooperating with Mr. Mueller."

It was not clear what witnesses might appear before the grand jury or what evidence it might be accumulating or presented with.

Mueller was appointed special counsel in May by the Justice Department following the firing by Trump of FBI Director James Comey. He has since assembled a team of more than a dozen investigators, including current and former Justice Department prosecutors with experience in international bribery, organized crime and financial fraud.

That team has been working at an undisclosed location in Washington, so presenting evidence inside a federal courthouse in the city could be more convenient for the group of investigators than working out of Alexandria. Mueller also worked as a prosecutor in Washington before becoming FBI director, a job he held for 12 years.

A grand jury "increases the power of the prosecutors," said David Levine, law professor at the University of California Hastings College of Law. "Instead of asking for people to provide testimony, they can demand testimony under the penalty of perjury and under risk of contempt of court. And with respect to documents, instead of asking people for documents, they can demand documents. And so for example the tax returns, a subpoena can unlock those tax returns," he said.

News of the grand jury came as senators introduced two bipartisan bills aimed at protecting Mueller from being fired by Trump, with both parties signaling resistance to any White House effort to derail the investigation into Russian meddling in last year's election.

Trump's defense team has been looking into potential conflicts of interest among members of Mueller's team, such as past political contributions to Democrats including Hillary Clinton, and Trump has warned that any effort by Mueller to look into his finances would fall outside the scope of Mueller's appointment.

Under the regulations, Deputy Attorney General Rod Rosenstein is the government official empowered to fire Mueller under limited circumstances, such as conflict of interest and dereliction of duty. Rosenstein, who appointed Mueller, has publicly said he has seen no basis for firing him.

Oakland, California - Aug. 3, 2017

1. David Levine looks at news story on phone

2. Screen showing news story about grand jury in Russia probe

3. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"What we've learned is that special counsel Mueller and the lawyers working with him are using a grand jury to further their investigation into the questions about Russian collusion and related areas such as financial transactions and other matters."

Washington, D.C. - June 21, 2017

4. AP Photo of former FBI director Robert Mueller arriving for meeting at Capitol Hill

Oakland, California - Aug. 3, 2017

5. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"It increases the power of the prosecutors. Instead of asking for people to provide testimony, they can demand testimony under the penalty of perjury and under risk of contempt of court. And with respect to documents, instead of asking people for documents, they can demand documents. And so for example the tax returns, a subpoena can unlock those tax returns."

Huntington, West Virginia - Aug. 3, 2017

6. AP Photo of President Donald Trump speaking at rally

Oakland, California - Aug. 3, 2017

7. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"If it's somebody in the United States, they are subject to subpoena. And that would include the president of the United States. Famously President Bill Clinton appeared before a grand jury. It turned out not very well for him."

Washington, D.C. - Dec. 11, 1998

8. AP Photo of President Bill Clinton walking to Rose Garden to deliver statement on impeachment

Oakland, California - Aug. 3, 2017

9. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"If I was in the White House, I would be concerned that the investigation has gone up a notch or appears to have gone up another notch. In short order probably people who are in the administration or former members of the administration or former members of the campaign will be getting subpoenas to testify and provide documents."

Washington, D.C. - June 21, 2017

10. AP Photo of former FBI director Robert Mueller arriving for meeting at Capitol Hill

Oakland, California - Aug. 3, 2017

11. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"And as the word gets around in the White House as to who is getting subpoenas and what is being asked, at least some members of the administration will obviously be getting more more nervous. This is why so many of them already have - the parlance is they've lawyered up. So many of those senior officials each have their own lawyer or series of lawyers because of their concerns of where this may lead."

Huntington, West Virginia - Aug. 3, 2017

12. AP Photo of President Donald Trump speaking at rally

Oakland, California - Aug. 3, 2017

13. SOUNDBITE (English) David Levine, law professor, University of California, Hastings College of the Law

"We're probably months and months away before we hear formally from Mr. Mueller as to whether and who might be indicted and for what."

14. David Levine looking at phone

California's top law enforcement official blasted his former congressional colleague, House Speaker Paul Ryan, on Friday for suggesting that a lack of political experience helps explain President Donald Trump's questionable interactions with James Comey when he was FBI director.

In an interview with The Associated Press, state Attorney General Xavier Becerra labeled Ryan an "accomplice" for defending what he termed Trump's incompetence or dereliction of his presidential duties. Becerra served in Congress prior to being appointed attorney general earlier this year.

"How dare you say it's a novice mistake?" Becerra said of comments by Ryan and others defending the president.

Becerra was referring to Trump's potentially illegal efforts to get Comey to drop the investigation into then-national security adviser Michael Flynn's interactions with Russian officials. Ryan said Thursday that Trump should be forgiven because he is "new at government" and "learning as he goes."

Becerra said ignorance of the law is not an acceptable excuse for Trump.

Ryan's spokeswoman, AshLee Strong, did not immediately respond to an email request seeking comment.

Becerra was appointed after former attorney general Kamala Harris, another vocal Trump critic, was elected to the U.S. Senate. He and other Democrats who control all major political offices in California have positioned the state as the front lines of resistance to many Trump administration policies.

Becerra said continued political theater in Washington won't stop California from enacting its own agenda on immigration, the environment and a host of other issues.

In a wide-ranging interview, Becerra also defended the death penalty, the state's cooperation with federal agents in fighting drugs and sex trafficking, and said he sees no sign yet of a federal crackdown on California's burgeoning recreational marijuana industry.

But he also promised to continue fighting Trump's agenda, bringing legal action and joining other states when necessary.

Becerra said he has tried to engage with the Trump administration without much success. His efforts to meet with Attorney General Jeff Sessions and Homeland Security Secretary John Kelly for more clarity on their plans to enforce federal immigration law have gone unmet despite multiple requests, Becerra said.

Meanwhile, California's Legislature is considering making California a "sanctuary state" by limiting how much state and local law enforcement officers may collaborate with the federal government's immigration enforcement efforts, as well as bills to make it harder for immigration authorities to raid businesses.

But even as state legislators work to resist federal enforcement, Becerra suggested there's room for collaboration between state officials and U.S. Immigration and Customs Enforcement, from sex trafficking to cracking down on illegal drug flow.

"I'm not trying to thwart ICE from doing its work, they're doing some really important stuff and we're doing some really important stuff with them," Becerra said. "And so it just helps to have some clarity and predictability."

On other topics, Becerra said:

— California could file climate-related lawsuits, but it will depend on what actions the Trump administration takes.

"We're going to continue to do what we've been doing," he said. "If someone wants to try to stop us, then they're probably going to run into me."

He pointed to his efforts to defend California's energy efficiency and emissions standards.

He said he has received no response from the Freedom of Information Act request he filed two months ago seeking documents he said could show conflicts of interest and ethics violations by U.S. Environmental Protection Agency Administrator Scott Pruitt.

Pruitt had sued his new agency multiple times while he was attorney general of Oklahoma.

— Becerra defended the death penalty as constitutional, but stressed that officials need to be "cautious." There are "too many cases" of people wrongfully sentenced to death row, he said.

— Becerra said he doesn't think the federal government will make a "comprehensive effort" to crack down on recreational marijuana industries in states like California that have legalized the drug.

"My sense is that they know that if they try to do something on a large scale then they're going to run into a real juggernaut against them," he said.

He added that he would defend California's marijuana industry if the federal government does try to crack down.

Sacramento - June 9, 2017

1. SOUNDBITE (English) Xavier Becerra, California Attorney General

"I would let prosecutors who dealt with this day in and day out pontificate on that. I will tell you to hear the director of the FBI with some pretty definitive clarity say that the president either lied or misrepresented what had gone on that takes you into an area that you rarely see, certainly from communications and activities involving the president. When you also find out that the actions by the president have consequences, not just for the investigation on the role that Russia played, but also in a potential cover-up -- you're in obstruction of justice territory. Can you prove all the elements of the obstruction of justice charge? We are only at the beginning of this investigation and already this much information has come out. Would anyone have said weeks into this investigation of Watergate that we would have discovered as much as we ultimately did? My sense was that this was a deep pool and Mueller hasn't even jumped into the water yet."

REPORTER: "What do you make of Speaker Ryan's response was essentially along the lines of 'well he's new at this.' The president's new at this he didn't really know what he was doing'? I wonder just what your take is ont he response."

"My immediate reaction was... hmm... is this the guy who's got his finger on the nuclear button as well and is that an excuse you said you would give to someone who runs for president who would have his hand on the nuclear button that he's still a new guy. Cut him some slack. I don't get it. I think it speaks volumes more about those who are defending Donald Trump more than Donald Trump. How dare you say that 'ah it's a novice mistake'? You are the president of the United States. This is not one of those those things where you can just say 'oops. I forgot to pay the bill, or sorry hundreds... thousands of kids aren't going to get their head start, oops I didn't realize that we're not supposed to interfere in some other country's affairs.' You go through the whole process of the campaign and you're ready to be president of the United States. For someone to try to defend the -- not incompetence -- than the dereliction of the president, in my book you're an accomplice."

REPORTER: "What would it take... you said a couple weeks ago at the convention that you were near impeachment territory. What do you think it would take for Speaker Ryan, your former Republican colleague in Congress to get there themselves?"

"Well, after yesterday's comments by Speaker Ryan, himself, I'm not sure if he's willing to excuse the potential for obstruction of justice, what else might they be willing to excuse? High crimes and misdemeanors can mean many things. I would belive that obstruction of justice would fit into that category. There are a lot of other things that would fit within that category as well. As Republicans demonstrated, they were willing to go that route in the late 1990's. If you did someone for not being totally candid about their definition of 'is' and what you did in terms of their personal life, then you should be willing to want to investigate what someone did with potential collusion with Russia and someone trying to potentially undermine our democratic elections."