Paper - Belfer Center for Science and International Affairs, Harvard Kennedy School

The Jimmy Hoffa Case 45 Years Later

  • John Wigle
| Feb. 01, 2021

Using Social Network Analysis to Clarify the Mystery

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Jimmy Hoffa was a prominent labor leader and fierce union organizer starting in the late 1930s and up through the 1960s. He rose through the ranks of the International Brotherhood of Teamsters to become its president, was eventually jailed, and barred from participating in union activities as a condition of a commutation by President Richard Nixon. On July 30, 1975 he disappeared while waiting to meet with business associates who were well-known Mafia figures. He was officially declared dead by a Michigan probate court in 1982,, and the mystery surrounding his disappearance has gone unsolved and has been turned into numerous books and two major motion picture films – one recent film was The Irishman. All these works, except for a handful of scholarly publications, have largely relied on suspects whose accounts have long since been debunked, leaving mystery and intrigue in their wake.

Jimmy Hoffa, right, talks with Robert F. Kennedy, left, counsel for the Senate Rackets Investigating Committee in Washington, D.C., Aug. 21, 1957.  (AP Photo)

At the time, there were many allegations of corruption within the Teamsters union and its close ties with the Mafia. Jimmy Hoffa famously squared off with senate counsel (and later Attorney General) Robert Kennedy during senate and Justice Department investigations into labor management and organized crime. Their feud was public. Hoffa was called to testify under oath before senate hearings in 1957.  Caught in a famous photograph from those hearings, Hoffa is subtly giving Robert Kennedy the middle finger.

Jimmy Hoffa was not a “made man” – an official member of the Sicilian Mafia – lacking the genetic pedigree required of its membership, but nonetheless his activities and interactions with the organization were representative of a very intimate association. Specifically, he often worked with organized crime when it was to the advantage of the union and its members. Although Hoffa was credited with keeping the Mafia in-check regarding union matters, Jack Goldsmith – a Hoffa scholar and Harvard Law professor – argues that Robert Kennedy’s assailing of Jimmy Hoff in the 1960s, and his eventual conviction and jail sentence unintentionally enabled organized crime to garner greater control of the Teamsters and its pension fund.

When Jimmy Hoffa attempted to return to the union presidency following his release from jail, it is believed the Mafia did not want him back in control given Jimmy’s tighter grip on the union’s business and its pension fund. Jimmy also threatened to expose the mob’s connections to the union and its use of the pension funds for loans that were beneficial to its corrupt plans and goals. As such, the Mafia set about plans to eliminate Jimmy Hoffa.

This fact pattern is of interest to contemporary scholars and crescendos around one critical question: Who were the chief suspects and likely culprits? There are as many theories about the people behind the murder as there are stars in the sky.

In this paper, I assert that using objective data and applying social network analysis – a mathematical framework – can clarify the dynamics of a network engaged in conspiracy-based crimes.,,  Academic literature is rife with examples of identifying cell leaders within terrorist networks or post-mortems on Enron using social network analysis.,, But this maybe one of the first academic papers to apply social network analysis to an unsolved cold case to identify key conspirators.

The first hurdle in executing this analysis was the lack of an objective dataset on Hoffa and his associated Mafia network.  As such, I generated a dataset that would be useful in social network analysis (SNA) modeling using three disparate and authoritative sources from:

The Federal Bureau of Investigation’s Hoffa case file and made available to the public through the Freedom of Information Act;

The published book of a law school professor with direct ties, knowledge, and familiarity with the suspects in the case; and

The published work of a journalist who is considered a leading expert on the Mafia in Detroit where Jimmy Hoffa disappeared and held most of his business interactions.

As such, the paper draws upon three authoritative sources from top-notch scholarly and professional investigative work on the Hoffa disappearance.  It then uses the power of mathematics and social network analysis on data from these sources to reexamine a cold case: probably a first-ever use of social network analysis for this purpose. This approach and methodology will help us place a spotlight on the likely culprits involved in the conspiracy to kidnap and murder Jimmy Hoffa.


An analysis of the Jimmy Hoffa network generated from data I develop from an FBI 1978 seventy-page chronology of events, Harvard Law professor Jack Goldsmith’s book In Hoffa’s Shadow, and Scott Burnstein’s book Motor City Mafia, suggests that three men are at the center of gravity in the disappearance and murder of Jimmy Hoffa.  All three men were members of Sicilian organized crime groups, one in Detroit, and two in New Jersey.  All three men were FBI key suspects at one time or another in the Hoffa investigation.  One suspect in particular had business dealings with Hoffa and stood to lose financially if Hoffa returned to power as president in the Teamsters Union. Additionally, one of the men was shot and killed on the street in New York City’s Little Italy, possibly for cooperating with the FBI about the Hoffa disappearance in exchange for a plea deal in a separate case of a Mafia-involved killing.

The three men are:

  • Anthony “Tony Pro” Provenzano, a mobster from New Jersey who frequently borrowed money from the Teamsters pension fund;
  • Salvatore “Sally Bugs” Briguglio, a mobster from New Jersey who was Tony Pro’s hitman; and finally
  • Anthony “Tony Jack” Giacalone, a Detroit mobster who was an associate of Hoffa.

All three were pursued by the FBI and the US Department of Justice in the Hoffa investigation, but asserted their 5th amendment right from self-incrimination during a Detroit federal grand jury investigation into the Hoffa disappearance. The social network analysis metrics of all three men were the highest of anyone within the network suggesting the three men are likely to have had intimate knowledge of the disappearance even if they were not personally involved in the abduction. All three men are now deceased.

For more information on this publication: Belfer Communications Office
For Academic Citation: Wigle, John. “The Jimmy Hoffa Case 45 Years Later.” Paper, Belfer Center for Science and International Affairs, Harvard Kennedy School, February 1, 2021.

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