Advances in fingermark age determination techniques
Fingermarks have long been recognized as one of the most reliable and valuable evidence for personal identification. In practice, fingerprint analysis primarily concentrates on latent fingerprint visualization. However, fingerprint visualization techniques don’t always enable individualization when fingermarks collected in crime scenes are fragmentary, ambiguous, or deformed. Age determination techniques based on physical and chemical changes in fingerprints over time have attracted the researchers’ attention in recent years. Nevertheless, components in fingerprints are liable to factors including donor features, deposition conditions, substrate properties, environmental conditions and revealing methods. All the influences mainly contribute to unreliable outcomes of age estimation. Recent developments in fingermark age determination have moved forward to more precise approaches. The advanced methods can be classified into two categories including techniques based on the modifications of physical characteristics or chemical composition characteristics. Herein, the review includes the five types of variables in the aging process. The methodologies are subsequently highlighted along with their advantages and disadvantages. Furthermore, an emphasis on the utilization of photography, optical, microscopy and electrochemical methods, as well as vibrational spectroscopy and mass spectrometry (MS) techniques are summarized in detail.