Human DNA has a very significant role in crime scene investigation by bringing the culprit in front of justice and in exonerating the innocent. Domestic animals such as cats and dogs living in human habitat deposit hairs can aid in finding the suspect related to a crime. The botanical specimen found in the victim’s body can relate it to the suspect or aids in understanding whether the deceased body was moved from one place to another.
The hair of the victims or the assailant’s cat might be unknowingly deposited in the crime scene. If an animal is involved in the attack of a victim and resulted in death, the animal in custody is an only source of DNA information to know the animal committed the crime or not.
Non-Human DNA Testing
Cat have 18 pair of autosomes and two sex chromosomes namely X and Y. A new DNA test using STR markers named ‘Meowplex‘ was developed for testing domestic cats. A gender identification marker was also included in this assay. The Canadian Police on Edward Island found a body of Shirley Duguay buried in a shallow grave along with a leather jacket stained with a victim’s blood and long white hairs of a cat. Her common-law husband Beamish had a cat named snowball. The hairs of cat DNA matched the blood sample of the cat. Beamish was arrested for murdering Duguay and was arrested 8 months after she was killed.
STR markers for dog DNA testing have been developed and characterized on 38 pairs of autosomes and x chromosomes of a domestic dog. Canines mitochondrial DNA posses two hypervariable regions similar to that of human DNA.
Two primary areas are focused on Plant DNA testing. First is the linking of plant material to the suspect or victim’s place or to the crime scene. The second is the linking of marijuana in crime scene investigations. Marijuana is one of the illegal substances associated with crime scene investigations. Several STR markers have been developed for identifying the genome of marijuana and the markers are highly polymorphic.
Soil is abundant with bacteria and fungi. The DNA of the soil microbes aids in differentiating the soil from one place to another. Microbial DNA in the soil that sticks to the shoes and clothing of the victim or suspect aids in forensic investigations.
Endangered and exotic animal species are illegally exploited for their skin husk and meat. Individuals who exploit animals are identified using Genetic testing. The U.S. Fish and Wildlife Service has a Forensic Laboratory in Oregon, USA that does species identification using DNA.
Fundamentals of Forensic DNA Typing