FINAL by: OSAC Program Office; Version 2, December 1, 2020 1

OSAC RESEARCH NEEDS ASSESSMENT FORM

Title of research need: Consistency of Examiner Evaluation of Distance Determination GSR Patterns

Keyword(s): Muzzle-to-target distance determination; Gunshot Residue, bracketing, distance 

determination, range estimation

Submitting subcommittee(s): Firearms & Toolmarks Date Approved: March 5, 2021

(If SAC review identifies additional subcommittees, add them to the box above.)

Background Information:

1. Does this research need address a gap(s) in a current or planned standard? (ex.: Field identification system 

for on scene opioid detection and confirmation)

This Research Need has two parts: The first is to evaluate the use of a standard process of creating known distances in 

performing muzzle to garment distance determinations. This would then be used to study and better characterize the 

amount of variance observed in gunshot residue patterns when known variables (e.g. target material, ammunition, 

muzzle to target distance, firearm) are unchanged. The second need is to evaluate the variance of examiner 

interpretation and reporting of distance determination with the goal of standardizing bracket ranges for reporting 

muzzle to target distances.

2. Are you aware of any ongoing research that may address this research need that has not yet been published 

(e.g., research presented in conference proceedings, studies that you or a colleague have participated in but 

have yet to be published)?

Unknown

3. Key bibliographic references relating to this research need: (ex.: Toll, L., Standifer, K. M., Massotte, D., eds. 

(2019). Current Topics in Opioid Research. Lausanne: Frontiers Media SA. doi: 10.3389/978-2-88963-180-3)

• Nichols, R., Gunshot Proximity Testing: A Comprehensive Primer in the Background, Variables and Examination of 

Issues Regarding Muzzle-to-Target Distance Determinations

• AFTE Journal, 2004, Vol. 36, No. 3 Smith, Rebecca, Differences in Smokeless Propellant Grain Morphology: 

Predictable Effects on Muzzle-to-Target Distance Determination

• AFTE Journal, 2015, Vol. 47, No. 3 SWGGUN Guidelines for Gunshot Residue Distance Determinations

• AFTE Journal, 2012, Vol. 44, No. 4 Crego, Lynette, Distance Determination Results When Utilizing the Same Make, 

Model and Barrel Length Firearms

• AFTE Journal, 2011, Vol. 43, No. 4
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4. Review the annual operational/research needs published by the National Institute of Justice (NIJ) at 

https://nij.ojp.gov/topics/articles/forensic-science-research-and-development-technology-working-groupoperational#latest? Is your research need identified by NIJ?

Yes, “Understanding of the cognitive processes involved in pattern recognition as applied to forensic comparative 

analysis”.

5. In what ways would the research results improve current laboratory capabilities?

The research could lead to a more consistent process when developing witness panels or known test distances for the 

entire community when performing distance determinations. Further, if able to achieve a standard reporting range 

this would provide more consistent reporting across the entire community.

6. In what ways would the research results improve understanding of the scientific basis for the 

subcommittee(s)?

The basis and concepts of distance determination testing are well established. However, there may be variability in 

the production and interpretation of known distance patterns; therefore, this research may result a more systematic 

approach.

7. In what ways would the research results improve services to the criminal justice system?

The criminal justice system would be served by having more consistent analysis and reported distance brackets.

8. Status assessment (I, II, III, or IV): III

Major gap in 

current 

knowledge

Minor gap in 

current 

knowledge

No or limited

current research is 

being conducted I III

Existing current 

research is being 

conducted II IV

This research need has been identified by one or more subcommittees of OSAC and is being provided as an 

informational resource to the community.