WASHINGTON — Seymour Glanzer, a lawyer whose five decades of practice ranged from the prosecution of the original Watergate break-in defendants to the defense of the American convicted in the Washington car-bomb attack that killed former Chilean ambassador Orlando Letelier, died April 3 at a hospital in the District of Columbia. He was 91.
The cause was heart ailments, said a daughter, Judy Slate.
Mr. Glanzer was an assistant US attorney and had more than a decade of federal legal experience dismantling business scams and frauds when he became one of three prosecutors of the initial Watergate defendants.
In his 11 months in that role, he helped win convictions or guilty pleas from all seven of the men charged in the 1972 break-in at Democratic National Committee headquarters. The men, linked to the Nixon White House, were attempting to plant eavesdropping devices at the DNC offices at the Watergate building complex.
After the first Watergate trial, Mr. Glanzer participated in the investigation of the ‘‘coverup conspiracy,’’ which led to the indictments of Nixon Attorney General John Mitchell, Chief of Staff H.R. Haldeman, White House counsel John Dean, and presidential aide John D. Ehrlichman. The fallout from the prosecution ultimately led to the resignation of President Nixon in August 1974.
As a Watergate prosecutor, Mr. Glanzer had a ‘‘reputation as a ‘buzz saw’ when interrogating a witness,’’ according to The New York Times. One friend told the paper that he was so thorough in his prosecutorial preparation that he ‘‘never goes into a courtroom without the handcuffs ready.’’
In 1974, Mr. Glanzer became a partner in the law firm of what is now Dickstein Shapiro and maintained his affiliation with the firm until his death. His clients included Frank Fitzsimmons, who succeeded the imprisoned James R. Hoffa as leader of the Teamsters union; and Michael V. Townley, a US citizen accused of conspiring with Chile’s secret police to assassinate Letelier.
Letelier had served as a diplomat and foreign minister under Chile’s Marxist leader Salvador Allende, who was ousted in a military coup in 1973, and was an outspoken opponent of the coup leader turned dictator Augusto Pinochet.
On Sept. 21, 1976, Letelier and an American co-worker, Ronni Moffitt, who was riding with him, were killed when their car exploded — at the time, one of the first terrorists acts committed on US soil.
Mr. Glanzer negotiated with prosecutors an agreement that, in exchange for a guilty plea and a promise of cooperation with the government, Townley would be immune from further prosecution and would serve a minimum prison sentence.
After serving 62 months in prison for the murder conspiracy, Townley was paroled in 1983 and placed in the federal witness protection program. He testified for the government in the prosecution of other conspirators involved in the Letelier bombing and was granted immunity from extradition to Argentina, where he was wanted in another car-bombing murder.
Mr. Glanzer — a New York City native, graduate of Juilliard School of music, and Army veteran of World War II — said little on the record about his role in the Townley-Letelier case other than the observation that ‘‘a lawyer’s job is to handle hot potatoes, and some potatoes are hotter than others.’’