Forensic identification
Forensic identification is the application of forensic science, or "forensics", and technology to identify specific objects from the trace evidence they leave, often at a crime scene or the scene of an accident. Forensic means "for the courts".
Animal identification[edit]
Wildlife forensics[edit]
There are many different applications for wildlife forensics and below are only some of the procedures and processes used to distinguish species.
Species identification: The importance of species identification is most prominent in animal populations that are illegally hunted, harvested, and traded,[26] such as rhinoceroses, lions, and African elephants. In order to distinguish which species is which, mtDNA, or mitochondrial DNA, is the most used genetic marker because it is easier to type from highly decomposed and processed tissue compared to nuclear DNA.[27] Additionally, the mitochondrial DNA has multiple copies per cell,[27] which is another reason it's frequently used. When nuclear DNA is used, certain segments of the strands are amplified in order to compare those to segments of mitochondrial DNA. This comparison is used to figure out related genes and species proximity since distant relatives of animals are closer in proximity in the gene tree.[28] That being said, the comparison process demands precision because mistakes can easily be made due to genes evolving and mutating in the evolution of species.[29]
Determination of geographic origin: Determining the origin of a certain species aids research in population numbers and lineage data.[26] Phylogenetic studies are most often used to find the broad geographic area of which a species reside.[30] For example, in California seahorses were being sold for traditional medicinal purposes and the phylogenetic data of those seahorses led researchers to find their origin and from which population they came from and what species they were.[31] In addition to phylogenetic data, assignment tests are used to find the probability of a species belonging to or originating from a specific population and genetic markers of a specimen are utilized.[32][33][34][35] These types of tests are most accurate when all potential population's data have been gathered. Statistical analyses are used in assignment tests based on an individual's microsatellites or Amplified Fragment Length Polymorphisms (AFLPs).[32][35][36][37] Using microsatellites in these studies is more favorable than AFLPs because the AFLPs required non-degraded tissue samples and higher errors have been reported when using AFLPs.[36][38]
Domestic animal forensics[edit]
Domestic animals such as dogs and cats can be utilized to help solve criminal cases. These can include homicides, sexual assaults, or robberies. DNA evidence from dogs alone have helped over 20 criminal cases in Great Britain and the U.S. since 1996.[39] However, there are very few laboratories that are able to process and analyze evidence or data from domestic animals.[40] Forensics can be used in animal attacks as well. In cases such as dog attacks, the hair, blood, and saliva surrounding the wounds a victim has can be analyzed to find a match for the attacker.[41] In the competitive realm, DNA analysis is used in many cases to find illegal substances in racehorses by urine samples and comparisons of STRs.[42][43][44]
Applications[edit]
Sometimes, manufacturers and film distributors may intentionally leave subtle forensic markings on their products to identify them in case of piracy or involvement in a crime. (Cf. watermark, digital watermark, steganography. DNA marking.)