Editing Single-bullet theory (section)

===Original bullet lead analysis by Vincent Guinn===
Warren Commission documents released after the publication of its report revealed that the FBI had arranged for bullet CE&nbsp;399 and the various fragments found in the car and in Governor Connally's wounds to be examined using [[neutron activation analysis]] (NAA). NAA is a precise, non-destructive method of determining the relative concentrations of trace elements in a sample of matter. The data from the tests performed for the FBI were inconclusive as to the origins of the fragments.<ref>Letter from J. Edgar Hoover to Commission Counsel Lee Rankin, July 8, 1964. Exhibit F-332A, 1 HSCA 558 [http://www.history-matters.com/archive/jfk/hsca/reportvols/vol1/html/HSCA_Vol1_0281b.htm]</ref>

In 1978 the HSCA asked physicist Vincent P. Guinn to review the NAA data and conduct new tests. Guinn did so and presented his results and analysis to the Committee. Guinn stated that initially he agreed with the earlier conclusion. After examining the old and new NAA data further, he concluded that all the fragments probably came from two bullets, one of which was the whole bullet, CE&nbsp;399.<ref>{{cite web|url=http://www.history-matters.com/archive/jfk/hsca/reportvols/vol1/html/HSCA_Vol1_0248a.htm |title=History Matters Archive - HSCA Hearings - Volume I, pg |publisher=History-matters.com |access-date=August 3, 2010}}</ref>

Guinn compared antimony concentrations of Exhibits CE&nbsp;840, 843 and 567 with that of Exhibits CE&nbsp;399 and CE&nbsp;842 and concluded that the data supported the single-bullet theory in that all the bullet lead in the car and wounds originated from no more than two bullets.<ref name="history-matters.com">{{cite web|url=http://www.history-matters.com/archive/jfk/hsca/reportvols/vol1/html/HSCA_Vol1_0269a.htm |title=History Matters Archive - HSCA Hearings - Volume I, pg |publisher=History-matters.com |access-date=August 3, 2010}}</ref>