Blood is the most commonly found biological evidence in majority of the crime scenes. Besides blood as a questioned sample, peripheral blood is often collected as a reference sample to be analyzed parallelly. The reference blood samples are collected in a controlled environment from the blood donors. Such blood samples are preserved either in an EDTA vial or an FTA card. Similarly, the blood stains as questioned samples are either collected from the crime scene or from the body of the victim/suspect/deceased. The questioned blood stain from the crime scene is collected either by the forensic expert or the investigating officer, whereas, the sample from the victim/suspect/deceased is collected by the medico-legal expert or the autopsy surgeon. Besides appropriate collection and preservation of blood samples, a proper set of documents also needs to be submitted along with the blood samples. Identification form or the blood collection form should be prepared while collecting the reference blood sample from the donor. Similarly, seizure memo, medico-legal certificate and/or autopsy report should be prepared while collecting blood sample from the victim/suspect/deceased. In both the cases, chain of custody form should be prepared and maintained in each step of forensic investigation.