Uncovering crucial facts that have shaped major events
and high-stakes legal battles.

Since our founding in 1984 by former Senate Watergate Committee assistant counsel Terry F. Lenzner, IGI has consistently been at the forefront of private investigations. Our reputation as a leader in the field comes from our commitment to the truth. We deliver exceptional outcomes for our clients with integrity and commitment to upholding the highest ethical standards. Our results have made us a standout choice to clients for the past forty years.

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IGI meeting in boardroom DC offices

Our Team, Our Values

IGI’s investigations are driven by an interdisciplinary approach with our team of former prosecutors, investigators, researchers, analysts and forensic accountants and computer forensics experts, who come from the White House, federal law enforcement, intelligence agencies, the financial services industry, and investigative journalism.

The legal perspective, insight, and quality control of attorneys from our in-house law firm, the Lenzner Firm, P.C., ensure our unwavering adherence to the highest level of professional and ethical standards.

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“Washington's premiere investigative firm."
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Our History

Upholding Terry Lenzner’s legacy and his commitment to uncovering facts.

Former Senate Watergate Committee Counsel, Terry F. Lenzner founded IGI in 1984. Under his leadership, IGI became one of the leading investigative firms in the United States, conducting a wide range of high-profile and sensitive investigations for a diverse clientele of prominent private and public entities and individuals.

Before founding IGI, Terry served as a trial attorney in the Civil Rights Division of the U.S. Department of Justice.  In 1964, he investigated the murder of three civil rights workers—an infamous event that inspired the film Mississippi Burning.  Lenzner also supervised the U.S. Department of Justice’s grand jury inquiry into events that occurred in Selma, Alabama in 1965. He then joined the Organized Crime Division of the U.S. Attorney’s Office for the Southern District of New York, and was later named by Donald Rumsfeld to be Director of the Office of Economic Opportunity’s Legal Service Program, where he supervised 2,500 attorneys.  Lenzner later served as Assistant Chief Counsel to the Senate Watergate Committee, which investigated the burglary at the Democratic National Committee headquarters at the Watergate office complex, as well as the subsequent cover-up. In that capacity, he authored and personally served the first Congressional subpoena of a sitting U.S. President.

In private practice, Lenzner uncovered cost overruns of the Alaska oil pipeline and investigated the circumstances of Princess Diana’s death. Lenzner also worked with President Clinton’s defense team during the impeachment hearings.

"He saw the Watergate investigation as an example of Democrats and Republicans working together, without a preconceived outcome, and acknowledging common sets of facts as they were revealed. 'Our country has forgotten the lessons of Watergate,' he wrote. One result, he added, is that 'the truth is what you can get enough people to believe.' ” (from his obituary in the Wall Street Journal, October 2020).

Lenzner was a graduate of Harvard College and Harvard Law School and was a member of the Harvard University Board of Overseers from 1970 to 1976. In 2013, Lenzner wrote a memoir about his varied career and high profile cases, The Investigator. He passed away in 2020.

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Terry Lenzner delivering subpoena to R. Nixon Watergate

Lenzner on his way to delivering the subpoena to President Richard Nixon.

Nixon Subpoena
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The Nixon subpoena (Click to view larger version)

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