Good Help Essay

627 Words3 Pages
* To help prosecute suspected criminals, law enforcement officials employ the services of serologists, professionals who are trained to analyze blood samples, perform semen analyses and interpret the significance of bloodstains. The outcome of a criminal case can be affected significantly by a serologist's testimony. Analyzing Blood Samples * Suspicious stains that are discovered at the scene of a crime are not always what they appear to be. In fact, even if they are confirmed as blood stains, a serologist must eliminate the possibility that they came from an animal rather than a human being. Once blood is verified to be human in origin, serologists are able to make educated guesses regarding the age, sex and blood group of the person from whom it came. Even a small amount of blood--such as that discovered under the fingernails of a victim who scratched at an attacker during an assault--can be examined under a microscope to yield clues to the attacker's identity. Semen Identification * In a sexual assault investigation, serologists are enlisted to examine fluid swabbed from assault victims and charged with the task of identifying the presence of spermatozoa, or sperm cells. Semen analysis is conducted through microscopic examination. "Once semen has been identified, it can be analyzed to characterize chemical substances that will indicate the ABO blood type of the donor," according to the book "Practical Aspects of Rape Investigation," by FBI agent Robert R. Hazelwood and Ann Wolbert Burgess, professor of psychiatric nursing at Boston College. Explaining Patterns * In the wake of a violent crime, bloodstain patterns provide criminal investigators with such information as the speed with which an injured person attempted to flee from the scene or the location and description of an attack. For example, sustained motion may be indicated by blood that is
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