Sullivan, who was once described by the Washington Post as the ''legal equivalent of nuclear war'', and who defended Lieutenant-Colonel Oliver North in the Iran Contra scandal in the late 1980s, has over forty years of litigation experience in federal and state courts all over the country.
Known widely as the best of the best, he practices in a broad range of areas, including complex commercial litigation, the defense of major law firms in malpractice cases, products liability, and high-profile criminal litigation. Clients have included Fortune 500 companies that were involved in criminal investigations, litigation, or government regulatory matters.
Significant cases have included his representation of the four Federal Bureau of Investigation (FBI) agents involved in the controversial Ruby Ridge shootout in 1992, as well as his defense of former Secretary of Housing and Urban Development (HUD) Henry Cisneros against accusations of making false statements to the FBI during a background check.
Sullivan also served as counsel for billionaire chipmaker and co-founder of Broadcom, Henry Nicholas, when he was charged with violating securities and narcotics laws. He also defended U.S. Senator Ted Stevens in the federal grand jury and court proceedings regarding his failure to properly report gifts. In addition, recently, he defended Dick Grasso, CEO of the New York Stock Exchange, against charges brought by the Attorney General of New York.
Both his peers and the media have repeatedly recognized Mr. Sullivan as one of todays most accomplished and respected trial attorneys. He is listed regularly by the National Law Journal ''America's One Hundred Most Influential Lawyers'', and in 2010, The National Law Journal listed Mr. Sullivan among ''The Most Influential Lawyers of the Decade'' in litigation. The Legal Times listed him as the ''Best Counsel Available'' in Washington and identified him as ''the leader'' of the group. In 2006, Legal Times identified him as ''The Leading Lawyer in White Collar Criminal Defense'' as chosen by the D.C. legal community. The Washingtonian magazine called him ''D.C.'s Toughest Lawyer'', according to information at the Williams & Connolly
Mr. Sullivan speaks at various law schools, continuing professional education programs, as well as bar and judicial functions. According to Williams & Connolly's website, ''He is the senior member of Williams & Connolly's Executive Committee.''