Biological Specimenss In Homicide Cases

Describe examples of three biological specimens that can be analyzed using toxicology to provide evidence in a criminal case. Blood, urine, and liver. Blood can be analyzed is often the specimen of choice for detecting, quantifying and interpreting drugs and other toxicant concentrations. Concentrations of drugs and other toxicants in blood may be useful for establishing recent drug ingestion and to determine the effect of a drug on the deceased at the time of death, or at the time the blood was taken. Urine is the most common sample used for drug testing in the workplace, but it is not always available for post-mortem testing. Urine testing results do not directly correlate to drug effects at the time of sample collection because of the time it takes the body to eliminate these drugs or their metabolites (the body’s breakdown products) in the urine. Liver is a primary solid tissue for use in post-mortem toxicology because it is where the body metabolizes most drugs and toxicants. Many drugs become concentrated in the liver and can be found even when there are no levels in the blood. In this latter situation, …show more content…
Enough tissue must be obtained for both histopathologic and microbiologic examination. Histopathologic examination is used to distinguish neoplastic from inflammatory lesions and acute from chronic inflammations. For example, the sensitivity of fluorescent antibody stain for Chlamydia trachomatis is higher when endocervical cells are obtained with a cytobrush than with a swab. The sensitivity may also be affected by the stage of the disease at which the specimen is collected. For example, the detection of herpes simplex virus by fluorescence, immunology, or culture is highest when specimens from lesions in the vesicular stage of infection are