Meet senior Judge Raymond J. Dearie, the special master appointed in Trump document probe.

The Department of Justice's investigation into the alleged mishandling of classified material by former President Donald Trump was delayed in early September when U.S. District Judge Aileen Cannon, ruled that the documents seized during an Aug. 8 raid of his Mar-a-Lago residence first must be reviewed by a special master.

The documents seized were alleged to have been taken from the White House to Trump's private residence, a move the DOJ alleges could violate various federal statutes. Cannon granted a request by Trump's legal team that a special master should examine thousands of documents including 103 marked classified before the DOJ could move forward.

The Department of Justice then filed a motion requesting Cannon lift this order. Cannon, a Trump-nominated judge who serves in the Southern District of Florida, formally denied the DOJ request Thursday, instead appointing a special master recommended by the Trump team and agreed upon by the government: Raymond J. Dearie.

Dearie held his first hearing in the case on Tuesday Sept. 21, in which he pressed Trump's legal team on claims the former president had made about declassifying documents that contained highly sensitive national security intelligence which were later found in his Mar-a-Lago residence.

"You can't have your cake and eat it," Dearie chided Trump's lawyers, signaling they would ultimately have to produce evidence indicating these records were in fact declassified.

Judge Dearie's explosive first hearing: Lawyers for Trump, DOJ clash over classified records, access to Mar-a-Lago documents

Not his 'first rodeo': Inside look at some of Raymond Dearie's biggest cases

Here's what you need to know about the man now front and center in the investigation:

Who is Raymond Dearie?

Judge Raymond J. Dearie is a former U.S. Attorney for the Eastern District of New York. He was in the position from 1982 to 1986.

After that, he served as a chief judge for that same district from 2007 to 2011. He is now a judge on "senior status," meaning he is semi-retired but still presides from time to time. The Justice Department noted that Dearie continues to hear cases and said the court would need to determine if serving as a special master would run afoul of restrictions on outside employment.

Read our coverage on the Mar A Lago raid: What we know about handling classified documents

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How old is Raymond Dearie?

Judge Dearie is 78. He was appointed in 1986 as a federal judge in New York by then President Ronald Reagan. Prior to that he has served as U.S. Attorney for the Eastern District of New York.

Read the DOJ's affidavit: Takeaways from the Mar-a-Lago search affidavit

Where did Raymond Dearie go to college?

Judge Dearie graduated with a law degree from St. John's University in Queens, New York in 1969.

He earned his undergraduate degree from Fairfield University in Connecticut.

Where was Raymond Dearie a federal judge?

A native New Yorker himself, Judge Dearie served as a federal judge for the Eastern District of New York which covers parts of New York City and Long Island.

What does Dearie's record look like?

Andrew Weissmann, a former federal prosecutor, and a former senior member of former FBI Director Robert Mueller's team told NPR that Dearie had a reputation in the legal community of being fair, describing him as the "platonic ideal of what you want in a judge."

Dearie has a background in matters of national security as well, serving on the U.S. Foreign Intelligence Surveillance Court for seven years.

He also spent some of the later years of his legal career advocating for sentencing reform. NPR cited a speech he gave to the New York Criminal Bar Association in 2016 in which Dearie said: "If society relies on the jail cell alone to bring relief to the streets of New York or Chicago, or to fight the heroin epidemic that has invaded our communities, little will change."

More on DOJ probe: Justice Department subpoenas dozens of Trump aides in apparent escalation of investigation

What does Dearie's appointment mean for the DOJ's case?

The Department of Justice plans to appeal Judge Cannon's ruling, arguing that though she allowed for the team to continue its investigation into possible crimes, it will be difficult without access to those 103 classified files.

Judge Cannon's ruling was viewed as narrow – a 10-page stay which appointed Dearie and gave him until Nov. 30 to finish reviewing the documents. The cost of Dearie's review will be paid for by Trump and his legal team since he requested a special master.

Classified materials, explained: What are the types of 'classified' government documents? Explaining 'Top Secret' and more.

This article originally appeared on USA TODAY: Who is Raymond Dearie? Special master holds first hearing in DOJ probe.