As Attorney General, he was noted for personifying the "law-and-order" positions of the Nixon administration, amid several high-profile anti-Vietnam War demonstrations.

[5][6] During World War II, Mitchell served for three years in the United States Navy and attained the rank of lieutenant (junior grade) as a PT boat commander.

Stories Mitchell told about his naval service were later debunked, including having received the Silver Star and Purple Heart, served as John F. Kennedy's commanding officer, and saved the life of Pappy Boyington.

[9] Mitchell did not dispute when asked in an interview if the intent of such language was to create a "form of political elitism that bypasses the voter's right to a referendum or an initiative.

Allegedly, Mitchell also played a central role in covert attempts to sabotage the 1968 Paris Peace Accords which could have ended the Vietnam War (the “Chennault Affair”).

[13][14][15][16] After Nixon became president in January 1969, he appointed Mitchell as Attorney General of the United States while making an unprecedented direct appeal to FBI Director J. Edgar Hoover that the usual background investigation not be conducted.

[27][28] From the outset, Mitchell strove to suppress what many Americans saw as major threats to their safety: urban crime, black unrest, and war resistance.

As in the case of other government departments and agencies, EPA refers civil and criminal suits to the Department of Justice, which determines whether there is a base for prosecution and of course, if we find it so, we proceed with court action.... And today, I would like to announce that we are filing suit this morning against the Jones and Laughlin Steel Corporation for discharging substantial quantities of cyanide into the Cuyahoga River near Cleveland.

We are filing a civil suit to seek immediate injunctive relief under the Refuse Act of 1899 and the Federal Water Pollution Act to halt the discharge of these deleterious materials into the river.”[30] In an early sample of the "dirty tricks" that would later mark the 1971–72 campaign, Mitchell approved a $10,000 subsidy to employ an American Nazi Party faction in a bizarre effort to get Alabama Governor George Wallace off the ballots in California.

Mrs. Mitchell was held against her will in a California hotel room and forcibly sedated by a psychiatrist after a physical struggle with five men that left her needing stitches.

He admitted that he was briefed on January 27, 1972, while he was the attorney general, by G. Gordon Liddy on Operation Gemstone which proposed numerous illegal activities to support the reelection of President Nixon, including the use of prostitutes, kidnapping, and assaulting antiwar protestors.

Tape recordings made by President Nixon and the testimony of others involved confirmed that Mitchell had participated in meetings to plan the break-in of the Democratic Party's national headquarters in the Watergate Office Building.

[41] In addition, he had met with the president on at least three occasions to cover up White House involvement, using illegal means such as witness tampering, after the burglars were discovered and arrested.

[42] On January 1, 1975, Mitchell, who was represented by the criminal defense attorney William G. Hundley, was found guilty of conspiracy, obstruction of justice, and perjury.

[43] Mitchell was sentenced on February 21 to two-and-a-half to eight years in prison for his role in the Watergate break-in and cover-up, which he dubbed the "White House horrors".