Asked by Judiciary Chairman Sen. Dick Durbin whether the Jan. 6 insurrection was a "one-off" domestic terrorism event, Garland said he didn't think it was, citing comments by FBI Director Chris Wray who has outlined the rise in threat of domestic terrorism in recent years.

Garland said he agreed that we are currently facing "a more dangerous period" than the nation faced when he was overseeing the investigation of the Oklahoma City bombing. He said while he has no inside information about the department's investigation into the Capitol rioters, he said "it looks like an extremely aggressive and perfectly appropriate beginning to an investigation" adding it will be his first priority and first briefing upon his return to the department if he's confirmed.

Asked about the Trump Administration's child separations, Garland said the policy was "shameful" and said he would ensure cooperation from Justice Department into the committee's investigation of the policy.

"I can't imagine anything worse than tearing parents from their children and we will provide all the cooperation we possibly can," Garland said.

Garland was asked whether he will let special counsel John Durham finish his investigation, Garland said he had no information on it but has no reason from what he currently knows to believe Durham should be removed. Garland said it will be among his first briefings upon confirmation as Attorney General.

Garland declined to answer a question from Grassley about whether he will commit to defending the death sentence penalties for certain individuals like the Boston marathon bomber, noting they are pending cases.

Grassley also asked whether Garland had any discussions with Biden about the investigation into Hunter Biden.

"I have not. The president made abundantly clear in every public statement before and after my nomination that the decisions about investigations and prosecutions will be left to the justice department," Garland said. "That was the reason that I was willing to take on this job, and so the answer to your question is no."

-ABC News' Alexander Mallin

Judiciary Chairman Sen. Dick Durbin, D-Illinois, used his opening statement to cast Garland's nomination as "one of the most critical in department history," after summarizing what he described as corruption and abuses under former President Trump and former Attorney General Bill Barr.

Durbin lauded Garland's record both on the federal bench and his time as a Justice Department prosecutor, while outlining the challenges he will face upon his return to the department.  Durbin closed his opening statement by noting that upon his confirmation Garland will be forced to grapple with the Justice Department's sprawling probe of the Jan. 6 insurrection, referencing Trump's role in inciting the mob but stopping short of directly calling on Garland to investigate the former president.

Ranking member of the Senate Judiciary Committee, Sen. Chuck Grassley, R-Iowa, used his remarks to preview what will likely be a priority of Republicans over the next two days -- securing commitments from Garland that upon confirmation he will not seek to fire special counsel John Durham, appointed by his predecessor AG Barr to investigate the origins of the Russia probe, and not interfering with the U.S. attorney in Delaware's ongoing investigation of President Biden's son, Hunter Biden. Grassley also indicated they'll press Garland on investigating Biden's family's financial dealings that he sought to investigate along with Sen. Ron Johnson, R-Wisc., leading up to last year's election.

Garland was formally introduced to the committee by Sen. Chris Van Hollen, D-Md, and Sen. Tammy Duckworth, D-Ill., who gave glowing remarks summarizing Garland's resume, expressing optimism in how he'll be able to tackle the challenges the department and the country currently faces.

-ABC News' Alexander Mallin

Judge Merrick Garland's confirmation hearing for his nomination as the nation's next attorney general is now underway in front of the Senate Judiciary Committee. Garland is expected to face tough questions on everything from combating the nation's domestic terror crisis in the wake of the Jan. 6 insurrection, calls for racial justice and equity in the criminal justice system, restoring the department's independence and how he'll handle politically-sensitive investigations into President Joe Biden's son Hunter and special counsel John Durham's probe into the origins of the Russia investigation.

"The President nominates the Attorney General to be the lawyer -- not for any individual, but for the people of the United States," Garland told the Senate Judiciary Committee in his opening statement according to remarks released over the weekend.

Garland's appearance comes nearly five years after Senate Republicans, including some currently sitting on the committee he'll be in front of today, refused to hold hearings on his nomination by former President Barack Obama to replace the late Justice Antonin Scalia on the Supreme Court.

However, based on remarks from Sen. Chuck Grassley, R-Iowa, who is expected to address their previously stonewalling of Garland's nomination by shifting to attack Democrats for their treatment of Supreme Court Justice Brett Kavanaugh during his confirmation.

"So yes, it’s true that I didn’t give him a hearing. I also didn’t mischaracterize his record. I didn’t attack his character. I didn’t go through his high-school yearbook. I didn’t make his wife leave the hearing in tears. I took a position on hearings, and I stuck to it," Grassley will say.

Garland could also be forced to walk a fine line as he faces potential questions of whether his department should launch investigations into former President Donald Trump for his role in inciting the Jan. 6 riot at the Capitol, after Senate Minority Leader Mitch McConnell recently raised the prospect after his vote against convicting Trump that the ex-president still be held accountable by the criminal justice system.

If confirmed, Garland will bring extensive background experience in the justice system to his role overseeing the department's more than 110,000 employees -- from serving more than two decades in the federal judiciary to his time as a top DOJ prosecutor during the Clinton administration, overseeing major investigations into the Oklahoma City bombing, Unabomber Ted Kaczynski and the Atlanta Olympics bombings.

-ABC News' Alexander Mallin

Merrick Garland, Biden's pick for attorney general, could face tricky political questions during his confirmation hearing before the Senate Judiciary Committee today. In the wake of the Jan. 6 attack on the Capitol, Garland and Democrats are expected to point to Garland's work prosecuting the Oklahoma City bombing as evidence of his ability to investigate and prosecute domestic terrorism.

"If confirmed, I will supervise the prosecution of white supremacists and others who stormed the Capitol on January 6 – a heinous attack that sought to disrupt a cornerstone of our democracy: the peaceful transfer of power to a newly elected government,” Garland will say.

Garland's opening statement also conveys a commitment to equity, saying that upholding the Civil Rights Act remains "urgent" for the Department of Justice. Garland has received ample bipartisan support, ahead of his confirmation hearings before Senate Judiciary Monday and Tuesday, 61 former federal judges and a bipartisan group of more than 150 former Justice Department officials have penned letters in support of Garland's confirmation.

-ABC News' Alexander Mallin and Benjamin Siegel

Garland described the Jan. 6 insurrection at the Capitol as "the most heinous attack on the democratic processes I have ever seen and one I never expected to see in my lifetime." He added he will make sure to provide career prosecutors all the resources they need to carry out their investigations while also taking a broader look at the symptoms behind the country's domestic extremism problem.

Asked by Sen. Dianne Feinstein, D-Calif., whether the president "has the absolute right to do what he wants with the Justice Department," Garland said presidents are "constrained by the Constitution as are all government officials" and cited comments by Biden committing to not interfere with Justice Department matters. At the same time, Garland said that the Department of Justice is part of the executive branch and because of that, on policy matters they do "follow the lead of the president and the administration as long as it is consistent with the law." When asked who an attorney general represents when his interests conflict with the president's, Garland said the attorney general "represents the public interest, particularly and specifically as defined by the Constitution and the statutes of the United States."

Asked whether the president can order an attorney general to open or close an investigation, Garland said such a question was a hard one for constitutional law but that he did not expect it to be a question for himself given President Biden's statements assuring independence for the department.

Sen. Lindsey Graham, R-S.C., took a contentious tone with Garland in his line of questioning as he pressed him on multiple topics. At one point, when Graham asked Garland whether he thought former FBI Director Comey was a good FBI director, Garland declined to answer, which Graham said he found "stunning" because he thought Comey was terrible. Sen. Sheldon Whitehouse, D-R.I., pressed Garland on whether he would commit to investigating not only the rioters who attacked the Capitol on Jan. 6, but those "upstream" like the funders, organizers, ringleaders or others not actually at the Capitol.  Garland cited his past experience as a line prosecutor, noting "we begin with the people on the ground and we work our way up to those who are involved and further involved -- and we will pursue these leads wherever they take us."

Asked about whether he would end the Trump Justice Department's policy of generally stonewalling in the face of oversight requests from Congress, Garland committed to Whitehouse that the department would be "as responsive as possible" to any requests and "at the very least why if it can't answer a question or can't answer a letter." Garland also committed that he would work with Whitehouse on getting answers to the committee on requests that the Justice Department under Attorneys General Bill Barr and Jeff Sessions previously ignored.

In an exchange with Sen. John Cornyn, R-Texas, Garland committed that his personal politics will have no impact on prosecutions and investigations he oversees as attorney general. Asked what he would do if he was ordered to do something that he considered to be unlawful, Garland said he would first tell the president or whoever else was asking him that what they were ordering was unlawful and would resign if no alternative was accepted.

Asked by Sen. Amy Klobuchar, D-Minn., what he will do to improve morale in the department, Garland said he would on his first day make an oath to career prosecutors and agents "that my job is to protect them from partisan or other improper motives." Klobuchar then asked Garland whether he believes he'd need "additional authorities" to combat the country's domestic terrorism problem. Garland said while the department "is probably always looking for new tools ... the first thing we have to do is figure out whether the tools that we have are sufficient."

-ABC News' Alexander Mallin