Vincent Mroz
File:Vincent Mroz.JPG
Mroz displays the Luger pistol used in attempted assassination of Harry Truman. Press photo by Acme Photos.
Born(1922-03-11)March 11, 1922
Stanley, Wisconsin
DiedJuly 22, 2008(2008-07-22) (aged 86)
Adrian, Michigan
OccupationSecret Service agent
Spouse(s)Shirley Gammon
ChildrenBarbara and Gregory

Vincent Peter Mroz (March 11, 1922[1] – July 22, 2008) was a United States Secret Service agent and a United States Marine Corps veteran who served during World War II. In 1948, he was assigned to the presidential protection detail during the Harry S. Truman administration. In November 1950, Mroz shot one of two Puerto Rican nationalists who intended to assassinate President Truman. The man was later tried and imprisoned. The event was described as "the biggest gunfight in Secret Service history." The other nationalist was killed by a city police officer.

Mroz also served the presidential detail in the Dwight D. Eisenhower administration. He served with the Secret Service for 26 years, retiring in 1974 as the Deputy Assistant Director of the uniformed division.

Mroz had earlier played college football for the University of Michigan and Michigan State College.

Early yearsEdit

Vincent Mroz was born in Stanley, Wisconsin in 1922,[2] the son of Polish immigrants. His family later moved to East Chicago, Indiana. Mroz attended Washington High School as part of the Class of 1941.[3][4] In the fall of 1940, he played at the guard and tackle positions for the Washington High School football team.[5][6] At the time of the 1940 United States Census, he was living in East Chicago with his mother Antonia and his stepfather Martin Gzik.[7]

While in college, he played at the end position for the 1943 Michigan Wolverines football team that compiled an 8–1 record and was ranked No. 3 in the final AP Poll.[8]

Marriage and familyEdit

While still serving in the military as a lieutenant in the Marine Corps, Mroz married in October 1945 to Shirley Gamm at the Mt. Vernon Place Methodist Church in Washington, D.C.[3] They had two children, Barbara and Gregory Mroz.

Secret ServiceEdit

In 1948, Mroz went to work for the United States Secret Service.[9] He was assigned to the presidential protection detail for Harry S. Truman.[2]

1950 attack on Blair HouseEdit

File:Blair House daylight.jpg

In the fall of 1950, President Harry Truman's household was moved to Blair House on Lafayette Square while the White House was being renovated. He walked between there and his office in the West Wing. On November 1, 1950, Mroz engaged in a gunfight with two Puerto Rican nationalists who were storming Blair House in an assassination attempt on President Truman, upstairs in his quarters. One of the attackers, Oscar Collazo, shot a White House police officer at the guard house and began walking up the front steps of Blair House. After hearing the gunshots, Mroz ran through a basement corridor and stepped out of a street-level door on the east side of the House, where he opened fire on Collazo, shooting him in the chest and dropping him.[10][11] Mroz stopped Collazo on the outside steps with a bullet to the chest.[12][13][14][15] The incident has been described as "the biggest gunfight in Secret Service History."[14] Two other officers took part in the shooting of the attackers.

In 40 seconds, a total of 27 shots were exchanged among officers and attackers.[14] After the shooting ceased, Mroz discovered the body of the second attacker, Griselio Torresola, in the hedges adjacent to Blair House. He had been shot by officer Leslie Coffelt.[16] Mroz removed a gun from Torresola's body and found two magazines of ammunition in his pockets.[2]

In December 1951, President Truman, described as being "deeply moved," decorated Mroz and Floyd Boring with silver lapel buttons for their roles in saving him. He said they were "two straight-shooting secret service agents" and gave them [17] Collazo survived and was put on trial in February 1951. At the trial, Mroz identified Collazo, "He's sitting right there with a brown suit and a red tie and glasses on."[18] Collazo was convicted and imprisoned for decades.

Later yearsEdit

Mroz continued to work in the presidential protection detail during the Truman and later Dwight D. Eisenhower administrations.[2][19] From 1960 to 1962, Mroz was the chief of the Charleston, West Virginia office of the Secret Service, where he gained note for his investigation of a counterfeiting ring.[20][21][22][23] From 1963 to 1965, he was the head of the Kansas City office of the Secret Service.[9][24][25] He worked for the Secret Service for 26 years. By 1971, Mroz served as Deputy Assistant Director, Protective Services.[26] He retired in 1974 as the Deputy Assistant Director of the Uniformed Division.[2]

Later yearsEdit

Mroz moved to Adrian, Michigan for retirement. He lived there for 34 years before his death in July 2008.[2][27][28]


  1. BIRLS Death File for Vincent Mroz, born Mary 11, 1922, died July 22, 2008. U.S., Department of Veterans Affairs BIRLS Death File, 1850-2010 [database on-line].
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Patricia Sullivan (August 2, 2008). "Vincent Mroz, Elroy Sites; Sprang Into Action During Attempt on Truman's Life". The Washington Post.
  3. 3.0 3.1 "Shirley Gamm Bride of Lt. Vincent Mroz". Mason City Globe-Gazette, Mason City, Iowa: p. 7. November 2, 1945.
  4. "Vincent Mroz Is Safety Council Representative". Hammond Times: p. 17. March 3, 1940.
  5. "Washington Sets Trap for Hammond Touchdown Twins". Hammond Times. September 27, 1940.
  6. "Senators May Cut Figure In Western Race". Hammond Times: p. 15. September 12, 1940.
  7. Census entry for Vincent Mroz, age 18, born in Wisconsin. 1940 United States Federal Census [database on-line]. Year: 1940; Census Place: East Chicago, Lake, Indiana; Roll: T627_1065; Page: 7A; Enumeration District: 45-39.
  9. 9.0 9.1 "Mroz Heads K.C. Office". Lawrence Journal-World. February 5, 1963.,2491833&dq=mroz+secret-service&hl=en.
  10. Excerpts from the history of the United States Secret Service, 1865-1975. Department of the Treasury, United States Secret Service. 1978. p. 30.
  11. Stephen Hunter and John Bainbridge Jr. (October 9, 2005). "American Gunfight; A little-remembered shootout near Lafayette Square left President Harry Truman's life hanging in the balance". The Washington Post: p. W.16.'s+life+hanging+in+the+balance&pqatl=google.
  12. James W. Clarke (2012). Defining Danger: American Assassins and the New Domestic Terrorists. Transaction Publishers. p. 66.("Secret Service Agent Vincent P. Mroz stopped Collazo on the entrance steps with a single shot to the chest. Collazo fell unconscious face-down ...")
  13. Scott P. Johnson. Trials of the Century: An Encyclopedia of Popular Culture and Law, Volume 1. p. 388.("A few seconds later, Collazo was seriously wounded when he was shot in the chest by Vincent P. Mroz, a Secret Service agent.")
  14. 14.0 14.1 14.2 Ronald Kessler (2010). In the President's Secret Service. Random House Digital, Inc.. p. 8.("The biggest gunfight in Secret Service history was over in forty seconds. A total of twenty-seven shots had been fired.")
  15. Robert J. Donovan (1996). Tumultuous Years: The Presidency of Harry S. Truman, 1949-1953. University of Missouri Press. p. 294.(as Collazo walked up the steps to the front door, he was "pinned down" by bullets from Mroz and two others)
  16. Hunter, Stephen; Bainbridge, Jr., John (2005). American Gunfight: The Plot To Kill Harry Truman – And The Shoot-Out That Stopped It. New York: Simon & Schuster. p. 251. ISBN 978-0-7432-6068-8.
  17. "Decorate Men Who Saved President". The Charleroi Mail, Charleroi, Penn.: p. 2. December 13, 1950.
  18. "Guard Identifies Truman Assailant". Spokane Daily Chronicle. February 28, 1951.,1147077&dq=mroz+truman&hl=en.
  19. "Secret Service Agent Witnesses To History". Long Beach Press-Telegram. May 11, 2003.
  20. "Counterfeit Bills Passed at Cadiz". Coshocton Tribune, Coshocton, Ohio: p. 20. June 16, 1960.
  21. "Charge Ohioans With Passing Bogus Bills". The Newark Advocate, Newark, Ohio: p. 6. March 25, 1961.
  22. "Counterfeiters In Eastern Ohio, Merchants Warned". The Daily Courier, Connellsville, Penn.: p. 2. June 17, 1960.
  23. "Bogus $10 Bills In Huntingdon Same as Wheeling". The Daily Courier: p. 13. August 28, 1962.
  24. "New Secret Service Chief". Salina Journal: p. 13. February 5, 1963.
  25. "22 Bogus $20 Bills Found in Kansas City". Moberly Monitor-Index, Moberly, Missouri: p. 8. May 25, 1965.
  26. Hearing of the Committee on Appropriations of the United States Congress. U.S. Government Printing Office. 1971. p. 216.
  27. "V. Mroz, E. Sites, helped foil attack on Truman". Newsday, Long Island, NY. August 4, 2008.
  28. "Obituary". Daily Telegram, Adrian, Michigan. July 25, 2008.
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