Naval Reserve with 38 years of service in the diverse roles of both a carrier pilot and a Judge Advocate General Corps (JAG) lawyer.

He had personally piloted a Ford Tri-Motor, the Goodyear Blimp, a Soviet MiG-15, a Czech L-39, a Chinese CJ-6, a French Fouga Magister, and many other unique, antique, or historic aircraft.

After receiving his wings in 1953, he deployed to the western Pacific and flew both day and night missions in the Grumman AF Guardian from the USS Princeton (CVS-37).

[10] After completing law school, Cristol became a civil lawyer, and served as special assistant attorney general of Florida.

While working on his Ph.D. thesis (from the late 1980s into the 1990s), Cristol analyzed the official investigations of the USS Liberty incident of June 8, 1967,[12] in which Israeli forces attacked an American ship, resulting in a significant loss of life.

In 2004 the agency released audio tapes which had been collected by an NSA unit aboard a Navy Lockheed EC-121 Warning Star aircraft flying near the scene of the USS Liberty attack.

[16] Cristol's second book, The Liberty Incident Revealed: The Definitive Account of the 1967 Israeli Attack on the U.S. Navy Spy Ship, was published by the Naval Institute Press in 2013.

One of the Naval History and Heritage Command’s webpages pertaining to the USS Liberty incident cites this book as its primary source.

[18] He spoke in favor of Israel during a 2004 U.S. State Department symposium that was convened in about the Six-Day War in response to the findings of the 2003 Moorer Commission and the 2004 release of Captain Ward Boston’s affidavit pertaining to the USS Liberty incident.

Cristol was an Angel Flight volunteer pilot, flying people in need of transportation to and from regional medical centers for treatment.

In 2003, the Greater Miami Aviation Association honored Cristol with their Glenn Curtiss Award which recognizes the contributions of an individual to improve the South Florida community.