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Analysis of Alternative Light in the Detection and Visibility of Cutaneous Bruises

NCJ Number
Date Published
22 pages

This is the Final Summary Overview of the findings and methodology of a study with the goal of determining whether alternate light detects and improves the visibility of cutaneous bruises on individuals with differing skin colors through bruise resolution.


This involved determining which available alternate light sources (ALS) wavelengths and filters were most effective and the potential impact of bruise and subject factors. Bruising is one of the most common types of soft tissue injury noted on victims of violence; however, bruises can vary widely in their clinical presentation. Factors such as the subject’s skin color and the bruise’s age and depth can affect how bruises appear during physical assessment. Unidentified bruises may contribute to a disparity in the medical care and forensic investigation of victims, including those with darker skin color or who delay treatment that ages bruises. Although typical white lighting used in forensic clinical practice contains wavelengths of the entire visible spectrum, ALS refers to light of specific bandwidths. When using an ALS to examine the skin, some of the light is reflected to the observer and others transmit to deeper layers. Clinical research suggests an ALS with wavelength peaks of 365nm (UV) or 400-450nm (violet and blue) may improve the detection and visibility of bruises; however, existing studies lack diversity in skin color and/or a prospective, systematically controlled design. The current study was a multisite, longitudinal, randomized controlled trial with a crossover design. This report summarizes the methods used, with appended details in the published work. Study findings suggest alternative light is more effective in detecting bruises than white across diverse skin tones. Using 415nm (violet) or 450nm (blue) wavelengths with a yellow or orange filter significantly increased odds of detection. 4 tables and 33 references

Date Published: January 1, 2021