Computerized system and methods of ballistic analysis for gun identifiability and bullet-to-gun classifications

A computerized system for ballistic analysis comprising

• means for comparing land impressions on the surfaces of a plurality of control bullets, fired by a suspect gun, to one another in all possible relative orientations for the control bullets;
• means for computing a correlation coefficient for each land-to-land comparison between the control bullets;
• means for comparing land impressions on the surface of an evidence bullet with the land impressions on each of the control bullets in all possible relative orientations for the evidence bullet and the control bullets, respectively;
• means for computing a correlation coefficient for each land-to-land comparison between the evidence bullet and the control bullets, respectively;
• means for identifying a set of matching coefficients corresponding to the correlation coefficients for each pair of the control bullets in a relative orientation of greatest match;
• means for identifying a set of questioned coefficients for the evidence bullet and the control bullets corresponding to the correlation coefficients in which the evidence bullet is in a relative orientation of greatest match with each of the control bullets, respectively;
• means for statistically evaluating whether or not the set of matching coefficients is statistically equivalent to the set of questioned coefficients;
• and
• means for concluding the evidence bullet was fired by the suspect gun in response to a statistical evaluation that the sets of matching coefficients and questioned coefficients are statistically equivalent.

A computerized system for ballistic analysis comprising

• means for comparing land impressions on the surfaces of a plurality of control bullets, fired by a suspect gun, to one another in all possible relative orientations for the control bullets;
• means for computing a correlation coefficient for each land-to-land comparison;
• means for identifying a set of matching coefficients corresponding to the correlation coefficients for each pair of the control bullets in a relative orientation of greatest match;
• means for identifying a set of same-gun non-matching coefficients corresponding to the correlation coefficients for each pair of the control bullets in a non-matching relative orientation of less than greatest match;
• means for statistically evaluating whether or not the sets of matching coefficients and same-gun non-matching coefficients are statistically undistinguishable;
• means for concluding the suspect gun is identifiable in response to a statistical evaluation that the sets of matching coefficients and same-gun non-matching coefficients are not statistically undistinguishable;
• means for comparing land impressions on the surface of an evidence bullet with the land impressions on each of the control bullets in all possible relative orientations between the evidence bullet and the control bullets, respectively;
• means for computing a correlation coefficient for each land-to-land comparison between the evidence bullet and the control bullets, respectively;
• means for identifying a set of questioned coefficients for the evidence bullet and the control bullets corresponding to the correlation coefficients in which the evidence bullet is in a relative orientation of greatest match with each of the control bullets, respectively;
• means for statistically evaluating whether or not the set of matching coefficients is statistically equivalent to the set of questioned coefficients;
• means for statistically evaluating whether or not the set of same-gun non-matching coefficients is statistically equivalent to the set of questioned coefficients;
• and
• means for concluding the evidence bullet was fired by the suspect gun in response to a statistical evaluation that the set of questioned coefficients is more statistically similar to the set of matching coefficients than to the set of same-gun non-matching coefficients.

A method of computerized ballistic analysis comprising the steps of

• comparing land impressions on the surfaces of a plurality of control bullets, fired by a suspect gun, to one another in all possible relative orientations for the control bullets;
• computing a correlation coefficient for each land-to-land comparison;
• identifying a set of matching coefficients corresponding to the correlation coefficients in which each pair of the control bullets is in a relative orientation of greatest match;
• identifying a set of non-matching coefficients;
• statistically evaluating whether or not the sets of matching coefficients and non-matching coefficients are statistically undistinguishable;
• and
• concluding the suspect gun is identifiable in response to a statistical evaluation that the sets of matching coefficients and non-matching coefficients are not statistically undistinguishable.

A method of computerized ballistic analysis comprising the steps of

• comparing land impressions on the surfaces of a plurality of control bullets, fired by a suspect gun, to one another in all possible relative orientations for the control bullets;
• computing a correlation coefficient for each land-to-land comparison between the control bullets;
• comparing land impressions on the surface of an evidence bullet with the land impressions on each of the control bullets in all possible relative orientations between the evidence bullet and the control bullets, respectively;
• computing a correlation coefficient for each land-to-land comparison between the evidence bullet and the control bullets, respectively;
• identifying a set of matching coefficients for the control bullets corresponding to the correlation coefficients in which each pair of the control bullets is in a relative orientation of greatest match;
• identifying a set of questioned coefficients for the evidence bullet and the control bullets corresponding to the correlation coefficients in which the evidence bullet is in a relative orientation of greatest match with each of the control bullets, respectively;
• statistically evaluating whether or not the set of matching coefficients is statistically equivalent to the set of questioned coefficients;
• and
• concluding the evidence bullet was fired by the suspect gun in response to a statistical evaluation that the sets of matching coefficients and questioned coefficients are statistically equivalent.

A method of computerized ballistic analysis comprising the steps of

• comparing land impressions on the surfaces of a plurality of control bullets, fired by a suspect gun, to one another in all possible relative orientations for the control bullets;
• computing a correlation coefficient for each land-to-land comparison;
• identifying a set of matching coefficients corresponding to the correlation coefficients in which each pair of the control bullets is in a relative orientation of greatest match;
• identifying a set of same-gun non-matching coefficients corresponding to the correlation coefficients in which each pair of the control bullets is in a non-matching relative orientation of less than greatest match;
• statistically evaluating whether or not the sets of matching coefficients and same-gun non-matching coefficients are statistically undistinguishable;
• concluding the suspect gun is identifiable in response to a statistical evaluation that the sets of matching coefficients and same-gun non-matching coefficients are not statistically undistinguishable;
• comparing land impressions on the surface of an evidence bullet with the land impressions on each of the control bullets in all possible relative orientations between the evidence bullet and each of the control bullets, respectively;
• computing a correlation coefficient for each land-to-land comparison between the evidence bullet and each of the control bullets, respectively;
• identifying a set of questioned coefficients for the evidence bullet and the control bullets corresponding to the correlation coefficients in which the evidence bullet is in a relative orientation of greatest match with each of the control bullets, respectively;
• statistically evaluating whether or not the set of matching coefficients is statistically equivalent to the set of questioned coefficients;
• statistically evaluating whether or not the set of same-gun non-matching coefficients is statistically equivalent to the set of questioned coefficients;
• and
• concluding the evidence bullet was fired by the suspect gun in response to a statistical evaluation that the sets of matching coefficients and questioned coefficients are more statistically similar than the sets of same-gun non-matching coefficients and questioned coefficients.