Test 1: Spectrographic Analysis
Oswald's paraffin casts were subjected to two analyses. Spectrographic analysis , the method normally used by the police, showed evidence of barium and antimony on Oswald's hands , but not on his cheek .
Test 2: Neutron Activation Analysis on Oswald
Spectrographic analysis was considered sufficiently reliable for criminal investigations, but in this case a more incisive test was also used. Neutron activation analysis, which is capable of identifying the presence of substances in quantities much to small to be captured by spectrographic analysis, also showed no incriminating quantities of residues on Oswald's cheek. The result was reported in an internal Warren Commission memo: " At best, the analysis shows that Oswald may have fired a pistol, although this is by no means certain. ... There is no basis for concluding that he also fired a rifle."
Test 3: Controlled Neutron Activation Analysis
In order to check the validity of the neutron activation analysis of Oswald's paraffin casts, a controlled test was made. Seven marksmen fired a rifle of the same type as that found on the sixth floor. The standard paraffin test was administered, and the paraffin casts were subjected to neutron activation analysis. All seven subjects showed substantial amounts of barium and antimony on their hands and more impotantly , on their cheeks.
The absence of significant quantities of residues on Oswald's cheek meant that he almost certainly had not fired a rifle that day.
