Go Forensic examination of poisoning | Forensic Medicine
Go

Forensic examination of poisoning

In cases of poisoning, a forensic medical examination is carried out to establish the cause of death or the connection of a health disorder with the action of toxic substances. The categorical nature of the expert’s conclusions largely depends on the data collected by the investigator on the circumstances of the incident and the nature of the alleged poisonous substance, the time elapsed from the moment the poison was taken and the onset of death, the nature of the medical care provided, the correctness of the removal and storage of objects from the corpse sent to a forensic chemical study, etc. In some cases, the expert comes to a categorical conclusion about poisoning with a certain poison, in others it does not exclude the possibility of poisoning with a certain poison or a certain group of toxic substances similar in their effects on the human body (clinical and morphological manifestations).

Suspicion that death has come from poisoning may also arise in cases of its unexpected occurrence, as if in full health. Diagnosis of death from poisoning often presents great difficulties associated with a number of objective and subjective reasons — incorrect assessment of laboratory data, a considerable time elapsed between the intake of poison and death, the similarity of clinical manifestations in cases of poisoning and some diseases, etc.

To prove the occurrence of poisoning, the materials collected by the investigation containing information about the circumstances of the incident are used; data of the forensic medical examination of the victim (for non-fatal poisonings) and autopsy data; data of forensic chemical and other laboratory studies of objects found at the scene, obtained from the attending physicians, seized during the autopsy.

Go

Materials of the investigation . The materials gathered by the investigation about the circumstances of the incident (for example, the simultaneous sudden illness or death of several people after sharing an alcoholic drink, with the development of the same painful symptoms in the victims) can directly indicate a possible poisoning. Residues of food and drink found at the scene, in containers, in various packaging materials from medicines, on the corpse (on the hands, at the mouth of the mouth and other parts of the body), on clothing and in its pockets can be found residues of poison taken by the injured . The presence of vomit can also indirectly serve as an indication of possible poisoning (the development of vomiting as a protective reaction of the body to intoxication), vomiting may contain traces of poison.

Inspection of the scene and the corpse should be carried out with the participation of a specialist in the field of forensic medicine. The physical evidence found that requires laboratory research is sent to the Bureau of Forensic Medicine.

Medical documents (outpatient records, medical records, etc.) containing a description of the course of poisoning and information about the nature of medical care should be presented to the expert in original.

Forensic medical examination of a corpse with suspected poisoning has its own characteristics. Before opening the sectional hall, it is necessary to ventilate in order to better capture and determine the nature of the smell felt when opening the cavities and internal organs of the corpse. Measures are taken to prevent accidental ingress of poison into the corpse when it is opened. Utensils for placing organs removed should be cleanly washed.

Thoroughly inspect the morgue clothes, linens and other items brought along with the corpse. On examination of garments, residues of poison, recipes for the production of poisonous medicinal substances, etc. can be detected.

Go

An external examination of a corpse can reveal an unusual coloring of cadaveric spots (bright pink-red color with carbon monoxide poisoning, brown or brownish with poisoning with poisons that form methemoglobin in the blood, etc.), jaundiced skin color with poisoning with arsenic hydrogen and mushroom poisoning; sharply expressed and rapidly numbing muscle stiffness (in case of poisoning with strychnine, cycutotoxin aconitine, etc.) (in case of poisoning with opium, morphine) or their sharp expansion (in case of poisoning with atropine, belladonna, asthmatol), irritation and ulceration on the mucous membrane of the lips and gums under the action of caustic poisons, grayish fringe on the gums with lead poisoning or mercury .

At the opening of cavities and organs, a smell specific to certain toxic substances may be felt.

In case of poisoning with many poisons, the ways of their elimination suffer - the kidneys, where characteristic changes can be detected. Many ingested substances quickly pass into the urine, are excreted in sweat, and can be detected on the deceased's linen and in the urine.

The data obtained in a forensic medical examination of a corpse must necessarily be compared with the data of the investigation and with the data obtained in a laboratory examination of the tissues and organs of the corpse.

A forensic examination is carried out in cases of poisoning that do not lead to death. Such examination of the victim is carried out both in the hospital and on an outpatient basis. The occurrence of poisoning in such cases is proved by investigative materials, medical documents on the provision of care and treatment, as well as examination data of the patient by an expert. Having established the fact of poisoning and the nature of its consequences, they determine the severity of these consequences, guided by the All-Union Rules for the Forensic Medical Determination of the Severity of Physical Injuries.

Great importance for the preparation of the diagnosis of poisoning with certain poison is attached to timely laboratory tests of vomit, wash water, and urine.

Not only the parts of the internal organs that were removed during the autopsy, but also the remains of drinks, food, vomit and other objects that may contain a toxic substance are sent to the forensic and other laboratory tests . The choice of the type of laboratory research of material evidence is determined by the nature of the alleged toxic substance. In accordance with this, chemical, physical (most often spectral), histological and biological (animal experiments), botanical and other research methods are used.

The results of a forensic chemical study should be carefully analyzed by a forensic expert.

A positive result of a forensic chemical study, taken in isolation, does not yet prove the fact of poisoning, and a negative one does not exclude it. In the internal organs of the corpse can be detected chemicals, including poisonous, which were not a source of poisoning, and entered the human body as a drug with food.

The results of a forensic chemical study on death from poisoning can be negative for various reasons: due to the rapid release of poison from the body, the transition of the poison to others that are not detectable during the forensic chemical study of the compound, improper removal and preservation of organs and tissues the method of research appropriate for a given poisoning, etc. The time elapsed from the time the poison was taken to death and the autopsy was discovered is largely determined by the preservation of the poison in the body, and therefore o, and the possibility of its detection in a forensic chemical study. However, a number of poisons can be found in corpses after a long time after death and burial, for example heavy metal salts.

If a death is suspected from poisoning, an exhumation is performed; The objects of a forensic chemical study may be the coffin planks, the surrounding land, where poisons from a corpse may fall.

Control questions
1. What is the significance of the investigation materials for the diagnosis of poisoning?
2. What are the features of the study of a corpse with suspected death from poisoning?
3. What data of external and internal examination of a corpse can be used to prove death from poisoning?
4. What organs and tissues are removed from a corpse in case of suspected death from poisoning and what is the procedure for their removal?
5. How should a forensic expert evaluate the results of a forensic chemical study (both positive and negative)?
6. What are the most common laboratory research methods used in the diagnosis of poisoning.