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The top Justice Department official who signed a letter erroneously telling lawmakers investigating "Operation Fast and Furious" that the Bureau of Alcohol, Tobacco, Firearms and Explosives never allowed guns to be sold to cartel members will be leaving the department to head up a law school.

Ronald Weich, the Justice Department's assistant attorney general for legislative affairs, will become the new dean of the University of Baltimore's school of law in July.

"During this time of considerable transition in legal education and the legal profession, it is important to have leadership with integrity and vision," University of Baltimore President Robert Bogomolny  said in a statement issued Wednesday. "Ron Weich embodies those qualities. I look forward to working with him, and I know our students, faculty, staff and alumni will be energized by his arrival."

News of Weich's pending departure comes nearly a month after he suggested Republicans on Capitol Hill were leaking sensitive information and five months after the Justice Department formally withdrew a Feb. 4, 2011, letter sent to Sen. Charles Grassley, R-Iowa, who was demanding answers from the ATF and Attorney General Eric Holder over allegations the agency had let suspected drug-smugglers buy hundreds of assault weapons.

"At the outset, the allegation ... that ATF 'sanctioned' or otherwise knowingly allowed the sale of assault weapons to a straw purchaser who then transported them into Mexico -- is false," Weich wrote Grassley at the time. "ATF makes every effort to interdict weapons that have been purchased illegally and prevent their transportation to Mexico."

Since then, a congressional investigation into "Fast and Furious" led by Grassley and House Oversight and Government Report Committee Chairman Darrel Issa, R-Calif., has helped reveal those claims as false.

In March, Weich sent a letter to Grassley and Issa noting that reporters were calling the Justice Department to ask about private documents relating to “an active criminal investigation,” including the case against one of the main targets of “Fast and Furious.”

“While we do not know who provided these letters to reporters, we are deeply disturbed that sensitive law enforcement information contained in them has now entered the public domain,” Weich wrote. “Since we know that you share our desire to bring dangerous arms traffickers to justice, we ask that you preserve the confidentiality of sensitive law enforcement information that may come into your possession.”

Launched in Arizona in late 2009, "Fast and Furious" planned to follow gun purchasers in hopes that suspects would lead them to the heads of Mexican cartels. But high-powered weapons tied to the investigation, whose targets purchased nearly 2,000 weapons over several months, ended up at crime scenes in Mexico and the United States, including the December 2010 murder of Border Patrol Agent Brian Terry

In recent months, the Justice Department disclosed several ATF operations similar to "Fast and Furious" conducted under the previous administration. And the head of the Justice Department's criminal division, Lanny Breuer, has acknowledged he learned of one of those "gunwalking" investigations, "Operation Wide Receiver," in April 2010 but never said anything to Holder.

The Feb. 4, 2011, letter signed by Weich -- and drafted in coordination with others in the department -- was formally withdrawn in December 2011.

Testifying before a House panel earlier this year, Holder said he did not believe the Justice Department intended to mislead Congress, noting his department has taken a "rare" move and made "wholesale deliberative material available" to lawmakers to help explain the genesis of "the inaccuracies that were contained in that letter."

"These documents show that department officials relied on information provided by supervisors from the relevant components in the best position to know the facts," Holder told lawmakers. "In subsequent interviews with congressional investigators, these supervisors stated that they did not know at the time that the information that they provided was inaccurate."

Weich himself testified before the House Oversight and Government Reform committee in June 2011. He mostly testified about the Justice Department's efforts to comply with congressional subpoenas, but he was also asked about the Feb. 4, 2011, letter.

"Every time the Justice Department sends a letter to Congress, it is true to the best of our knowledge at the time that we send it," he said. Still, he insisted again that ATF "doesn't sanction or approve of the transfer of weapons to Mexico."

It's unclear exactly when Weich would step down from the Justice Department. An email seeking comment from a Justice Department spokeswoman was not immediately returned.

Weich was confirmed by the Senate as assistant attorney general for legislative affairs in April 2009. He "heads the Office that represents the Department of Justice on all legislative and oversight matters before Congress," according to the Justice Department's website.

He previously served as Chief Counsel to Senate Majority Leader Harry Reid, D-Nev., and as counsel to former Sens. Edward Kennedy, D-Mass., and Arlen Specter, R-Penn., according to the Justice Department. Prior to that, he worked in private practice.

He is a native New Yorker, and a graduate of Columbia University and the Yale Law School.

The University of Baltimore School of Law is the sixth largest public law school in the country, with more than 1,100 students at its midtown campus, according to a press release from the school.

It was recently ranked among the top "Best Value" law schools by PreLaw magazine, the school said.