Version 1.1 / Date of Issue: 2.09.16 / Issuing Authority: Forensic Science Standards Board (FSSB)

OSAC RESEARCH NEEDS ASSESSMENT FORM

Title of research need: Evaluation of examiner conclusions utilizing a five-point scale 

Keyword(s): source conclusions; inconclusive; error rate; AFTE Range of Conclusions, firearms and 

toolmarks

Submitting subcommittee(s): Firearms and Toolmarks Date Approved:

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

Background Information:

1. Description of research need:

The AFTE Range of Conclusions defines five source conclusions which includes three descriptions of 

inconclusive; however, it is unclear how examiners practically apply the scale of inconclusive when 

comparing evidence. Past research has primarily focused on false positive and false negative error rates to 

determine the accuracy of examiners’ source conclusions. Research with an emphasis on all source 

conclusions, especially the range of inconclusive options, would assist in developing a better understanding 

of how examiners currently utilize and interpret the AFTE Range of Conclusions. 

2. Key bibliographic references relating to this research need:

Bruce Moran, A Report on the AFTE Theory of Identification and Range of Conclusions for Tool Mark 

Identification and Resulting Approaches to Casework, AFTE Journal, Vol. 34, No. 2, 2002.

David Baldwin, Stanley Bajic, Max Morris and Daniel Zamzow, A Study of False-Positive and False-Negative 

Error Rates in Cartridge Case Comparisons, Ames Laboratory USDOE Technical Report # IS-5207, April 2014.

Theory of Identification as it Relates to Toolmarks (including Range of Conclusions), AFTE Journal, Vol. 30, 

No 1, 1998.

3a. In what ways would the research results improve current laboratory capabilities?

It is anticipated that this research would allow for universal application in laboratory procedures when 

reporting conclusions of comparative examinations. 

3b. In what ways would the research results improve understanding of the scientific basis for the

subcommittee(s)?

Current laboratory practice varies in how inconclusive comparisons are reported. The AFTE Range of 

Conclusions classifies inconclusive as (A) some individual characteristics but insufficient for identification; 
Version 1.1 / Date of Issue: 2.09.16 / Issuing Authority: Forensic Science Standards Board (FSSB)

(B) insufficient agreement or disagreement of individual characteristics to make any determination; (C) 

some disagreement of individual characteristics, but insufficient for an elimination. It’s anticipated this 

research would provide insight into examiner decision making as it specifically applies to the inconclusive 

observations during a comparison. The Firearms and Toolmark subcommittee is drafting standards on 

firearm and toolmarks source conclusions and considering options (i.e. five-point scale vs. three point scale; 

inconclusive ranges, etc). This research would help guide the subcommittee with our standard 

development. 

This research could also help identify training that might be required to the firearms community as to the 

scale reporting or non-scale reporting of inconclusive comparisons.

3c. In what ways would the research results improve services to the criminal justice system?

The criminal justice system would benefit from a better understanding and a more universally applied 

standard of examiner conclusions and the articulation of those conclusions which would assist the trier of 

fact.

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

Approvals:

Subcommittee Approval date: 5/4/2018

(Approval is by majority vote of subcommittee. Once approved, forward to SAC.)

SAC

1. Does the SAC agree with the research need? Yes x No

2. Does the SAC agree with the status assessment? Yes x No

If no, what is the status assessment of the SAC:

Approval date: 5/4/2018

(Approval is by majority vote of SAC. Once approved, forward to NIST for posting.)