Forensic biology is the application of biology to associate a person(s), whether suspect or victim, to a location, an item (or collection of items), another person (victim or suspect, respectively). It can be utilized to further investigations for both criminal and civil cases. Two of the most important factors to be constantly considered throughout the collection, processing, and analysis of evidence, are the maintenance of chain of custody as well as contamination prevention, especially considering the nature of the majority of biological evidence.Forensic biology is incorporated into and is a significant aspect of numerous forensic disciplines, some of which include forensic anthropology, forensic entomology, forensic odontology, forensic pathology, forensic toxicology. When the phrase "forensic biology" is utilized, it is often regarded as synonymous with DNA analysis of biological evidence.
DNA, or deoxyribonucleic acid, is one of the most popular pieces of evidence to recover at a crime scene.[2] More often than not, evidence containing DNA is regarded to as biological evidence. With all of the substantial advances that have been made regarding DNA, biological evidence is recognized to be the golden standard in forensic science.
At the scene, biological evidence must be initially visibly recognized. Sometimes this is not always possible and the aid of an alternative light source, or ALS, is required. Once identified as a potential source, presumptive tests are conducted to establish the possibility of the specified biological presence (semen, saliva, blood, urine, etc.). If positive, samples are collected and submitted for analysis in the laboratory, where confirmatory tests and further tests are performed.
DNA analysis has numerous applications such as paternity testing, identifications of unknown human remains, cold case breakthroughs, as well as connecting suspects and/or victims to a piece(s) of evidence, a scene, or to another person (victim or suspect, respectively). Nuclear DNA evidence can be recovered from blood, semen, saliva, epithelial cells and hair (if the root is still intact).[2] Furthermore, Mitochondrial DNA can be recovered from the shaft of hair, bone and the roots of teeth. For most forensic DNA samples, STR analysis of autosomal short tandem repeats is performed in an attempt to individualize the sample to one person with a high degree of statistical confidence