DR. DAVID W. MANTIK, M.D., Ph.D., is a physicist and retired radiation oncologist who became a prominent JFK assassination researcher in 1991. He is known for his detailed forensic analyses of the medical evidence, particularly the autopsy photographs and X-rays, which he argues were altered to conceal a conspiracy.

Mantik holds a Ph.D. in physics and an M.D., having served as an associate professor of radiation sciences at Loma Linda University. He has visited the National Archives nine times to conduct precise measurements, specifically of the optical density of the original JFK skull X-rays.

Mantik's conclusions are based on his analysis of the medical evidence:

• Altered X-rays and Photographs: He argues that the extant autopsy X-rays and color photographs are forgeries. He uses a technique called densitometry (measuring optical density) to support his claim that a large metallic object visible in one X-ray was added later and that the images depict two entry wounds to the head—one from the rear and another from the right front—rather than a single shot from the rear.

• Pre-Autopsy Surgery: Mantik posits that Navy surgeons at Bethesda Naval Hospital performed pre-autopsy surgery on President Kennedy's head to remove evidence of the bullet from the forehead and sanitize the crime scene of bullet fragments and tracks.

• Multiple Shooters: His analysis suggests that two shots hit the President's head from the front/right front, which implies the presence of a second shooter (or more) in Dealey Plaza, contradicting the official finding of a lone gunman, Lee Harvey Oswald.

Mantik has contributed essays to several books and published his own detailed analyses. His books include:

• The Assassination of President John F. Kennedy: The Final Analysis
• John F. Kennedy's Head Wounds: A Final Synthesis — and a New Analysis of the Harper Fragment
• THE JFK ASSASSINATION DECODED: Criminal Forgery in the Autopsy Photographs and X-rays
• JFK Was Killed by Consensus: Dealey Plaza Was Just The Final Stop