Solution

Forensics

In the field of forensic science, crime scenes are often chaotic and cluttered, making the detection of key evidence, which is usually minute and hard to notice, extremely challenging. The Scanning Electron Microscope (SEM) is a high-resolution microscope with many advantages, such as rapid detection, good depth of field, and high magnification. It plays a crucial role in helping investigators quickly identify minute evidence that is invisible to the naked eye, thus enhancing the efficiency of case investigations.

01. SEM in Document Forgery Inspection
SEM allows non-destructive observation and analysis of documents, seals, and signatures, aiding experts in determining their authenticity and integrity. It can reveal minute details, material characteristics, and ink features, ensuring the authenticity and reliability of the evidence. This is significant in preventing forgery, combating counterfeiting, and protecting intellectual property.

02. SEM in Fingerprint Identification
SEM can be used for comparing physical evidence with suspects. By observing and measuring microscopic features on the surface of the evidence, such as ridge patterns and particle sizes, and comparing them with a suspect’s fingerprints or tool marks, it can determine the correlation. This is especially helpful in fingerprint and tool mark identification.

03. SEM in Material Evidence Identification
SEM can perform component analysis on various substances, helping experts determine the composition, structure, and properties of the materials. For example, in drug identification, SEM can confirm the composition and source of drugs by observing microscopic features on the sample surface and using supplementary equipment like energy-dispersive X-ray spectroscopy.

04. SEM in Evidence Analysis
SEM can observe the surface morphology of objects under examination at high resolution, providing detailed information about their microstructures. This plays a crucial role in forensic analysis at crime scenes, investigations, and case-solving. SEM technology can analyze microscopic characteristics of ballistic gunpowder, bullet fragments, or drugs, assisting judicial authorities in identifying the origin and characteristics of the evidence.

05. SEM in Forensic Examination
Diatom testing is used to determine if a body found in water died before or after entering the water. Diatoms cannot enter internal organs through the digestive tract but only through the alveolar walls into the bloodstream, circulating to various organs and bone marrow. Therefore, diatoms of the same type found in the water can be detected in the organs and bone marrow of drowning victims. Currently, the microwave digestion-vacuum filtration-scanning electron microscope method for diatom testing has become a routine and relatively reliable method in water body cases, and the related public safety industry standards have been officially published and implemented.

Using SEM, forensic experts can determine the presence of diatoms in the organs of bodies found in water, preliminarily identifying the cause of death and outlining the process of death.

As illustrated above, the Scanning Electron Microscope plays a wide-ranging and significant role in the forensic science industry. It provides high-resolution observation and analysis, helping experts gather detailed information about physical evidence, and offers scientific and objective evidence to judicial authorities, thereby facilitating the pursuit of justice.