Former Nebraska governor Charles Thone stands with a clay bust of himself in Lincoln in 2003. (Nati Harnik/AP)

Former Nebraska governor Charles Thone, who as a congressman in the late 1970s served on a committee that helped reinvestigate the killings of President John F. Kennedy and the Rev. Martin Luther King Jr. but dissented from its conspiratorial findings, died March 7 at his home in Lincoln, Neb. He was 94.

Mark Schorr, his longtime friend and law partner, confirmed the death but did not provide a specific cause.

Mr. Thone, a former Republican Party state chairman, represented Nebraska’s 1st Congressional District from 1971 to 1979. He served one term as governor, from 1979 to 1983, and lost his 1982 reelection bid to Bob Kerrey (D), a highly decorated Vietnam veteran who later served in the Senate.

In Congress, Mr. Thone served on the House Select Committee on Assassinations that formed in 1976 amid criticism that federal agencies had not followed or fully scrutinized every promising lead in the slayings of Kennedy in Dallas in 1963 and King, the civil rights activist, in Memphis in 1968.

A Senate inquiry had raised concerns that the CIA and FBI concealed evidence from Warren Commission investigators looking into the Kennedy death, and members of the Congressional Black Caucus pushed for a new review into King’s death, The Washington Post reported.

After more than two years and spending $5 million, the committee concluded that James Earl Ray had assassinated King, in keeping with the consensus, but it released a report suggesting the “high probability” of a wider conspiracy to kill Kennedy — specifically, raising doubts about the long-standing one-gunman theory. The committee did not provide hard evidence for the conclusion or name alleged conspirators but stoked the notion that the mafia, Cubans and labor leader Jimmy Hoffa were among the possible conspirators.

Those findings directly contradicted the Warren Commission, set up immediately after the Kennedy murder, that the troubled gunman Lee Harvey Oswald had acted alone in killing the president. Mr. Thone, who rejected claims of a conspiracy, refused to sign the special committee’s final report, later telling a Nebraska newspaper that in his judgment members of the Warren Commission “were rushed a little bit but, by and large, they got it right.”

Mr. Thone was born Jan. 4, 1924, and grew up on a 400-acre farm near Hartington, in northeastern Nebraska, where his family raised cattle, corn and hogs. After Army service in World War II, he graduated from the University of Nebraska’s law school in 1950.

As governor, Mr. Thone focused heavily on fiscal restraint, arguing in his 1980 State of the State address that “people want less government” and fewer laws. In 1979, he vetoed an attempt by lawmakers to abolish the death penalty.

Mr. Thone returned to private life after his tenure as governor and continued to work as a lawyer in Lincoln. In 2010, he led a coalition of governors to persuade voters to reject a ballot measure that would have eliminated the Nebraska state treasurer’s office. The measure failed.

Survivors include his wife, the former Ruth Raymond; and three daughters.