1. Dimensional Metrology Ballistics: Forensics Infrastructure Ted Vorburger, Guest Researcher John Song, T. Brian Renegar, Alan Zheng, Wei Chu,… Surface and Microform Metrology Group Also MSEL, ITL Martin Ols, Robert Thompson Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) Supported by EEEL Office of Law Enforcement Standards (OLES) Project Managers: Susan Ballou, Robert Thompson

2. Dimensional Metrology Contents A Short History of Four Ballistics Related Projects Accomplishments Highlights Project Status, an Observation, and Future Work

3. Dimensional Metrology A Short History of Four Ballistics Related Projects ATF recognizes the need for physical standards to verify control of automated optical microscopes in crime labs and contacts NIST OLES about developing standard bullets (1997) –OLES contacts MSEL… and holds a meeting –Participants point to MEL’s Surface & Microform Metr. Gp. (SMM) –OLES contacts SMM –Standard Bullet Project Initiated Feasibility of National Ballistics Imaging Databases (NBID) becomes an issue (2003) –ATF contacts OLES and SMM –OSTP and NIJ contact OLES, OLES contacts SMM –NBID Feasibility Project initiated Standard Casings Project initiated (2006) National Ballistics Imaging Comparison (NBIC) Project initiated (2008)

4. Dimensional Metrology Accomplishments NIST Standard Bullet Workshops held (2003, 2006) Standard Bullet released as SRM 2460 (2006) Report on NBID feasibility released (2007) Two NBIC Workshops held (2008, 2009) Concluding NBIC Workshop set for March 23

5. Dimensional Metrology Standard Reference Material (SRM) Bullets and Casings for Testing Ballistics Imaging Systems SRM 2460 Bullets, 40 units fabricated by Diamond Turning SRM 2461 Casings, about 175 units being fabricated by Electroforming (P. Rubert)

6. Dimensional Metrology Reproducibility of Standard Bullet Surfaces Signature A from virtual standard No. 1 land Signature B from #001 SRM standard bullet, No. 1 land Correlation: CCF max = 99.55% Signature difference D s = 0.92%

7. Dimensional Metrology Casing Regions Inspected for Identifying Characteristics Ejector Mark Breech Face Firing Pin

8. Dimensional Metrology Reproducibility of Standard Casings #001 vs. #002, CCFmax = 99.29 %

9. Dimensional Metrology cited heavily in National Academies Report (2008). www.mel.nist.gov/div821/webdocs- 13/NISTIR2007-7362.pdf MEL Report (NISTIR 7362)

10. Dimensional Metrology Conclusions of NISTIR 7362: For four different types of marked regions, -firing pin impressions from new guns, -firing pin impressions from used guns, -breech face impressions from new guns, -breech face impressions from used guns, surface topography analysis was more accurate for identifying matching casings than the optical microscopy technology in common use. However, the reproducibility of the surface topography was not high enough to be consistent with the accuracy requirements of a national database of new firearms

11. Dimensional Metrology Ideal Case –All Guns Distinguishable Graphical Approach Reference Casing Compared Casing ACCF max James Yen, ITL

12. Dimensional Metrology NBIDE Breech Face Impressions NIST Topography IBIS Microscopy

13. Dimensional Metrology National Ballistics Imaging Comparison Objective: To establish quality control procedures for automated ballistics inspections in crime labs and develop traceability to the ATF’s “Golden Images” of NIST’s Standard Bullets and Casings 19 Participants in 13 crime labs performing image acquisitions of Standard Bullets and Casings Data from all participants have been received. Example : Scores of correlations of five NBIC participants’ images to ATF “Golden Images” of Standard Bullets over  13 months

14. Dimensional Metrology Project Status, an Observation, and Future Work All data for the NBIC Project have been received from the participants and are currently being analyzed in collaboration with the Statistical Engineering Division, ITL The Third (and final) NBIC Workshop will be held on March 23 in St. Louis with the objective to draft and refine a quality control procedure for data acquisitions of standard bullets and casings. We have received, measured, and qualified 71 Standard Casings and are expecting the last shipment of 104 in March. We aim to certify and release SRM 2461 in FY09. Scientific impact:These projects enabled us to show that careful surface topography measurements with optical methods can correlate very closely with stylus methods. Based on the impressive reproducibility of electroformed standard casings, a new OLES project has been initiated in SMM/ PED/ MEL: “Toolmark Identification Proficiency & Validation Test Using Electroformed Replicas.”