Current Status and Prospects of Bloodstain Age Estimation Technology

Bloodstains are important biological evidence at violent crime scenes and contain rich information about the crime. The relatively accurate estimation of bloodstain age is of great significance for estimating the time of the crime, confirming or excluding the association of relevant persons (objects) with the case. In recent years, researchers at home and abroad have conducted extensive studies on the bloodstain age estimation from the aspects of bloodstain image and biochemical characteristics. This paper reviews the methods of bloodstain age estimation in the past two decades, discusses the obstacles of these methods in investigative practice, and provides an outlook on the development of bloodstain age estimation technology.