Fracture matching

DEFINITION: Inspection of the torn or broken edges of pieces of evidence to match the edges to their sources.

SIGNIFICANCE: In some cases, pieces of evidence found at crime scenes are not in their original states, having been broken, torn, or otherwise separated from other pieces. By matching the edges of two or more pieces of broken or torn material, forensic scientists may be able to determine the origins of these pieces of evidence and thus link them to possible suspects.

Fracture matching is similar to putting pieces of a puzzle together. Anything that can be broken, torn, or otherwise separated can be subjected to fracture matching. Forensic scientists are called upon to perform fracture matching with many different kinds of materials, including glass, cloth, metal, paint, paper, plastic, tape, and wood. Matching a bullet to the gun from which it was fired is considered a technique quite similar to fracture matching and is called toolmark analysis.

The combination of the composition of an object and the force used to separate it into pieces results in unique characteristics. For example, a piece of cloth, when ripped or cut, will never be ripped or cut apart in the same way twice. The cloth will have slight flaws that will span the rip or cut, and the force applied to separate it into different pieces can never be repeated identically. Because of these unique qualities, evidence of matched fractures is considered very strong scientific evidence in court.

In successful fracture matching, the broken pieces of an object can be realigned along the fracture point, and the fit of the broken pieces can be verified by markings on the surface or inside the broken object. Fracture matching can be done two-dimensionally, such as with cloth, paper, or tape, or three-dimensionally, such as with glass, metal, plastic, or wood. Investigators try to match fractures based on the chemical composition of the object, irregularities on the surface of the object, the shape of the break, and similarities between pieces of the object in age, deformation, or texture. Often, microscopic examination of the materials is necessary to determine the tiny matches in a fractured object.

Glass is a special material in terms of fracture matching; it is usually quite easy to match broken pieces of glass back together. The ridges that are formed in glass when it is broken (Wallner lines) are nearly always aligned to curve toward the point of impact. It is relatively easy for forensic scientists to use these ridges to match pieces of broken glass.

Tools can present another special kind of fracture-matching task. When metal tools are used with force against surfaces, such as to pry open windows or locked drawers, small shavings of metal from the tools are often left behind. Forensic scientists can match the markings seen on such small shavings against particular tools to determine whether those tools were used at certain crime scenes.

Fracture matching has provided important evidence in some seemingly unsolvable cases. For example, in a Florida case, a body that had been wrapped in sheets and taped with masking tape was found, and a suspect was apprehended. A forensic scientist was able to fracture-match one end of the masking tape found on the body with the corresponding end of a roll of masking tape found in the suspect’s home. Based on this and other corroborating evidence, the suspect was convicted of the murder.

Fracture matching evolved with technology to provide more robust, scientific validation for linking fragmented evidence to criminal acts, thereby solidifying its role in forensic investigations. In 2025, researchers were actively working on developing more objective, quantitative methods to measure and compare fracture surfaces in forensic analysis, moving beyond visual assessment and microscopic examination to incorporate three-dimensional topography data for improved reliability of matching. Artificial intelligence and machine learning have also been explored to analyze complex fracture patterns. Organizations like the American Society of Trace Evidence Examiners (ASTEE) worked to standardize and refine best practices for physical matching.

Bibliography

“American Society of Trace Evidence Examiners.” ASTEE, www.asteetrace.org/. Accessed 13 Jan. 2026.

Fisher, Barry, et al. Forensics Demystified: A Self-Teaching Guide. McGraw-Hill, 2007.

Gardner, Ross M. Practical Crime Scene Processing and Investigation. CRC Press, 2005. 

Mozayani, Ashraf, and Carla Noziglia, editors. The Forensic Laboratory Handbook: Procedures and Practice. Humana Press, 2006.

Nowak, Troy. “Physical Fit/Fracture Match Analysis.” American Society of Trace Evidence Examiners, 2024, www.asteetrace.org/fracture. Accessed 13 Jan. 2026.

Spaulding, Jamie S., and Gina M. Picconatto. “Characterization of Fracture Match Associations with Automated Image Processing.” Forensic Science International, vol. 342, Jan. 2023, doi:10.1016/j.forsciint.2022.111519. Accessed 13 Jan. 2026.

Thompson, Geoffrey Z., et al. “Quantitative Matching of Forensic Evidence Fragments Using Fracture Surface Topography and Statistical Learning.” Nature Communications, 8 Sept. 2024, doi:10.1038/s41467-024-51594-1. Accessed 13 Jan. 2026.