Detecting microfragments of glass in scar tissues

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Introduction

Identifying traumatic weapons in injuries caused by sharp objects has been the primary concern of investigative authorities. Currently, forensic medicine can determine the specific sharp traumatic object by its individual characteristics, including identifying established signs of injuries to the human skin caused by sharp objects with varying degrees of blade sharpness, composition, and design, as well as potential defects and conditions of injury [1].

Lacerations caused by glass shards through layers of clothing have been well-studied, despite such wounds externally appearing similar to injuries caused by other sharp objects, primarily knives [2, 3]. Detecting glass microshards in the tissues along the wound channel is a reliable method of confirming the impact of glass fragments on the skin, allowing to definitively determine if the wound was inflicted by glass [4].

The possibility of detecting glass microfragments in an already healed wound is uncertain. In 1962, I.M. Serebrennikov proposed a comprehensive methodology to examine skin scars [5], which was later augmented by the development of additional laboratory methods of research that consider the morphology of the scar tissue as well as the condition of surrounding and underlying tissues [6, 7]. These methods are currently used by forensic experts in the practical setting. A review of the literature revealed no information on the potential for detecting glass microfragments in scars.

Case presentation

Three men were reportedly observed to consume alcohol in an apartment in a district in Karelia, Russia. On the following morning, the body of one of the men was discovered with multiple stab wounds. The second man had sustained a chest wound and was transported to a regional hospital for further treatment. The third man was subsequently apprehended on suspicion of causing serious bodily harm to the other two men.

An expert conducted forensic medical examination of the surviving victim on the basis of the victim’s medical documents. Based on the surgical intervention protocol and characteristics of the described injury, the expert stated that the wound sutured by the surgeon was a stab wound caused by a stabbing and cutting object. The expert did not exclude the possibility that the wound was caused by a knife. The defendant categorically denied stabbing the victim and claimed that the victim was in a state of severe alcohol intoxication and had fallen repeatedly, including on a sideboard, the glass of which was found at the crime scene.

Four months later, the victim died of alcohol poisoning, and the lawyer of the suspect petitioned for a forensic examination to test the possibility of injury caused by broken glass from the sideboard.

Forensic medical examination of the victim revealed that the corpse was in a state of putrefactive transformation. A scar measuring 2×0.3 cm was found on the left side of the chest in the projection of the seventh intercostal space along the midclavicular line. The skin fragment that had the scar was subjected to medical and forensic examination to check for microfragments in soft tissues.

The medical and forensic department received a section of breast skin exhibiting noticeable putrefactive changes. The skin was flabby and moist and presented with a peeling epidermis, giving the appearance of a dirty gray colored film. Underneath, the dermis had a dirty brown color with a greenish tint and sharp putrefactive odor (Fig. 1). Examination of the central portions of the specimen using stereomicroscopy revealed a scar that exhibited the characteristics of a skin depression and an irregular spindle shape with a 30-mm length, 20 mm width, and 1 mm depth.

 

Fig. 1. A fragment of putrefactive changed skin, submitted for research.

 

The flap was treated with a vinegar–alcohol solution to reveal the features of the altered area on the skin. Following this, the skin exhibited discoloration, flattening, and swelling, thereby enhancing the visualization of the features of the altered area. The scar, which was in the form of a westernized area, measured 15 mm in length, 2–3 mm in width, and 1–2 mm in depth and resembled a trough. The edges had a rounded, sinuous morphology and converged at sharp angles at the ends. The bottom of the western area comprised dense connective tissue with whitish-brown color, an uneven texture, and fine granularity (Fig. 2).

 

Fig. 2. Type of scar after treating the skin in an acetic-alcohol solution (division value 1 mm).

 

For glass detection, the scar tissue was dissected and placed in a mixture of concentrated nitric and sulfuric acids. Then, the obtained mineralized material was diluted with distilled water in a ratio of 1:10 and filtered through paper filters. Following drying on their surface, stereomicroscopy revealed the presence of approximately 20 polygonal-shaped microparticles with dimensions ranging from 0.1×0.2×0.1 mm to 1.9×1.6×0.3 mm (Fig. 3).

 

Fig. 3. Type of microfragments of glass, found in scar tissue (division value 0.1 mm).

 

In oblique light, the microparticles had a translucent, colorless appearance with glare, sharp arcuately striated facets, and sharp serrated edges and resembled microshards of glass. Upon examination under polarized light, these microparticles were a dark gray color with a matte tint, indicating their optically inactive nature.

One drop of a 0.1% solution of cresol red in acetone was added as an indicator to the microparticles to determine their nature. After 40–50 seconds, under stereomicroscopic observation, a pink-violet coloration emerged, indicating the presence of an alkali agent. Overall, the obtained data, i.e., external appearance, resistance to a mixture of nitric and sulfuric acids, optical inactivity in polarized light, and positive color indicating the presence of glass, indicated that the microparticles found in the scar tissue were microshards of colorless, transparent glass. The microshards were further examined in a forensic laboratory, where chemical identification and matching with glass samples from the sideboard collected from the scene was conducted.

Discussion

The presented case provides an intriguing insight into the detection of glass microshards not only within the soft tissues along the wound channel but also in the scar formed after wound healing. This observation corroborates the hypothesis of trauma formation resulting from the impact of shattered glass, a phenomenon that has not been documented in previous studies. During examination, a scar was noted on the left side of the chest in the seventh intercostal space along the midclavicular line, and the scar tissue exhibited approximately 20 microscopic fragments of transparent colorless glass.

Conclusions

The methods applied in this case do not require any sophisticated technical equipment and can be widely used by a diverse range of experts. Their implementation has highlighted the potential of detecting glass microfragments in the soft tissues along the wound channel trajectory as well as in the scar tissue formed after wound healing. Our findings enabled the suspect to dismiss the allegation against him of causing injuries.

Additional information

Funding source. The article was supported by the grant of the Russian Science Foundation No. 23-25-10061, conducted jointly with the Republic of Karelia, and funded by the Venture Investment Fund of the Republic of Karelia.

Competing interests. The authors declare that they have no competing interests.

Authors’ contribution. All authors made a substantial contribution to the conception of the work, acquisition, analysis, interpretation of data for the work, drafting and revising the work, final approval of the version to be published and agree to be accountable for all aspects of the work. V.М. Antipov — data collection; O.S. Lavrukova, V.М. Antipov — draftig of the manuscript; I.A. Tolmachev, O.S. Lavrukova — critical revition of the manuscript for important intellectual content; I.A. Tolmachev, O.S. Lavrukova, V.М. Antipov — review and approve the final manuscript.

About the authors

Igor A. Tolmachev

Kirov Military medical academy

Email: 5154324@mail.ru
ORCID iD: 0000-0002-5893-520X
SPIN-code: 5794-9030

MD, Dr. Sci (Med.), Professor

Россия, Saint Petersburg

Vyacheslav M. Antipov

Forensic Medical Expertise Bureau of the Republic of Karelia

Email: sudmedexs7@mail.ru
ORCID iD: 0009-0000-8853-9518
SPIN-code: 8595-7589
Россия, Petrozavodsk

Olga S. Lavrukova

Petrozavodsk State University

Author for correspondence.
Email: olgalavrukova@yandex.ru
ORCID iD: 0000-0003-0620-9406
SPIN-code: 6395-8638

MD, Dr. Sci (Med.), Assistant Professor

Россия, Petrozavodsk

References

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