Francis Joseph Sheeran was born on October 25, 1920, in Darby, Pennsylvania, a blue-collar suburb of Philadelphia. He grew up in a working-class Irish-Swedish household, the son of Thomas Sheeran Jr. and Mary Agnes Hanson. His upbringing was rough—his father reportedly made him box for discipline.

In 1941, Sheeran enlisted in the U.S. Army before America formally entered World War II. He was assigned to the 45th Infantry Division, nicknamed "The Killer Division," and served for over 400 days in active combat—an unusually long stretch compared to the average soldier. His tours took him through North Africa, Italy, France, and into Germany. By his own account, he became desensitized to killing during this time, participating in revenge killings, unofficial executions of POWs, and reprisal killings at concentration camps.

After his military discharge in 1945, he returned to Pennsylvania and tried to settle into civilian life. He married Mary Leddy, with whom he had three daughters, but the marriage ended in divorce in 1968. He later married Irene Gray, and they had a daughter named Connie.

Frank Sheeran’s name became widely known not just for his high-ranking position within the Teamsters, but for his long-rumored involvement in some of the most notorious mob hits of the 20th century—including the still-unsolved disappearance of Jimmy Hoffa.

Sheeran’s criminal career began sometime in the mid-1950s when he met Russell Bufalino, a Pennsylvania mob boss. Bufalino allegedly introduced him into the world of organized crime. According to Sheeran, his first contract killing was that of Whispers DiTullio, a mobster who tried to involve Sheeran in a scheme to burn down a laundry business. When it was discovered that the business was partially owned by Angelo Bruno, the boss of the Philadelphia crime family, DiTullio was marked for death. Sheeran claimed he was ordered to kill him as retribution and compliance.

In the years that followed, Sheeran became deeply involved with the Teamsters union. Bufalino introduced him to union boss Jimmy Hoffa, and their relationship grew close—personally and professionally. Sheeran allegedly became Hoffa’s go-to enforcer. According to his own accounts and author Charles Brandt’s book I Heard You Paint Houses, Sheeran took part in several mob hits under Hoffa and Bufalino’s orders, including killings of rival union members and threats to the union’s control.

On April 7, 1972, Joe Gallo—a rising figure in the Colombo crime family—was gunned down at Umberto’s Clam House in Little Italy, Manhattan. While never charged, Sheeran is one of the main suspects in Gallo’s killing. He later admitted to this murder in interviews, though some accounts contradict this version of events.

However, it was Sheeran’s alleged role in the disappearance of Jimmy Hoffa that solidified his infamy. Hoffa vanished on July 30, 1975, in Detroit. According to Sheeran’s confession, he was tricked into luring Hoffa into a house under the pretense of a meeting. Once inside, he shot him twice in the back of the head. Sheeran claimed Hoffa’s body was cremated. No physical evidence ever conclusively linked him to the crime, though blood was found in the house he described—DNA testing later ruled it wasn’t Hoffa’s.

In 1980, Sheeran was indicted and convicted of labor racketeering tied to mob-run leasing firms. He was sentenced to 32 years in prison but was released after serving 13 due to declining health.

Frank Sheeran died of cancer in a nursing home on December 14, 2003, in West Chester, Pennsylvania.