Subclass Characteristics Workshop

This three-day (24 hour) workshop explores the historical development and evolution of  “Subclass Characteristics” and critically examines the use and definition of the term. A wide variety of firearm and tool manufacturing processes commonly encountered in the industry will be evaluated for subclass potential. Methods of recognizing potential subclass characteristics on tooled surfaces will be examined. Lab practices, interpretation, and legal challenges will be discussed. Emphasis will be on recognizing or eliminating the potential of subclass involvement, developing strategies to ensure identifications are not subclass in nature, and exploring documentation and report writing methods when subclass influence is suspected. This class combines lecture with heavy emphasis on laboratory/microscopic time, focusing on the examination of toolmarks made from numerous consecutively manufactured tools.

Examination and Comparison of Toolmarks

This 5-Day class introduces the participants to forensic toolmark examination, which is also the basis for firearm identification and comparison.  The basis of toolmark comparison is the determination of whether or not a particular tool was used to make a questioned mark. Students will gain specific knowledge related to examining toolmarks, producing exemplar marks, and comparing them to questioned marks. “Hands-on” training, which will include the examination of tools, toolmarks, the preparation of test marks, and the comparison of marks using a comparison microscope will be provided.

The Examination & Comparison of Cartridges, Cartridge Cases, Shotshells & Fired Shotshells

During this course, students will examine marks produced by various firearms on cartridges, cartridge cases, shotshells and fired shotshells. Striated and impressed marks from both cycling and firing a firearm will be examined and their probative value will be discussed. Although the class focuses on the marks routinely encountered in casework (breechface marks, firing pin impressions, chamber marks, ejection port marks, extractor marks, ejector marks and magazine marks), many less common marks will also be examined and compared. The firearms used to produce many of the exemplars will be available for students to examine. The evaluation of class, individual, and potential subclass characteristics will be addressed, and options for the wording of casework reports will be discussed.

The Examination & Comparison of Bullets & Shotshell Projectiles

This 5-Day class focuses on toolmarks transferred onto bullets by the barrels of firearms. Students will become familiar with examining the general rifling characteristics (GRC) of bullets in no gun cases in order to determine true caliber, nominal caliber and caliber designation. During the class, a GRC database will frequently be accessed in order to generate lists of possible firearms. Students will examine and compare bullets of various design in an attempt to find corresponding individual agreement. In addition, shotshell components will be examined to determine caliber and shot size. Bullets fired from consecutively manufactured barrels and several barrel casts will be available for evaluation of potential subclass characteristic carryover. Various options for the wording of casework reports will be discussed.