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Forensic Medicine Tasks, Working Methods and Techniques
Often, the examination of the opened corpse is not enough to determine the cause and mode of death. Then there are further investigations, for example on chemicals and poisons, medicines, alcohol or drugs, but also on the level of various hormones and other endogenous substances. These are detected under the microscope.
contents
- Dead and alive
- Duties of Legal Medicine
- Forensic pathology
- causes of death
- The morgue
- The death certificate
- The autopsy
- Determination of the time of death
- Deathchill
- bloodstains
- X-rays
- Computed Tomography
- sonography
- victims of violence
- gunshot wounds
- poisoning
- Forensic genetics
- proof of age
- Forensic dental analysis
- entomology
- Forensic outpatient clinic
Dead and alive
The forensic medicine not only clarifies deaths, as a popular in crime films image conveys, but also injuries, if they have a legal relevance. She is today a multidisciplinary science working with the most modern technology. The civil and criminal practice requires a separate field of study for forensic physicians, since they have little to do with medicine, chemistry and biology.
The tasks of legal medicine go far beyond investigating open corpses. (Image: fergregory / fotolia.com) Forensic medicine today is highly specialized and separates into various departments. The most important are Forensic Pathology, Forensic Genetics and Forensic Toxicology.
Duties of Legal Medicine
Forensic medicine includes thanatology, ie, examination of the dead, forensic traumatology, injury investigation, toxicology, venom search, drug research, and forensic molecular biology such as DNA probes. Likewise, the area includes forensic sexual medicine, traffic medicine, credibility assessments, medical assessment, treatment error reports, pedigree and insurance medicine.
Forensic pathology
Forensic pathologists investigate unclear deaths on behalf of prosecutors or police, especially if they happen suddenly. They autopsy the body to determine the cause of death, such as the time of death, reconstruct the chain of causation that led to death and, above all, determine in principle whether death occurred naturally.
If it is clear that this is a violent mode of death, for example, a car accident or a crime, the forensic traumatologists come on stage. They examine how the victims were killed.
The duties of forensic pathologists include judicially arranged mortuary shows and funeral openings, autopsies for professional associations and insurance companies, autopsies for private clients, the opening of exhumed bodies and crematorium shows.
Her work is of tremendous legal value. Thus, they make expert reports as to whether medical malpractice caused a death and reconstruct the incident that led to the demise biomechanically. They analyze the contents of the stomach in order to limit the time of death and capture the corpse's teeth, which can be compared with dental records to determine the identity of a dead person.
By matching dental records, forensic pathologists can clarify the identity of a dead person. (Image: Robert Kneschke / fotolia.com) causes of death
Possible causes of death are, for example: death by fall, by sharp or half-sharp objects, death by blunt objects or internal injuries. Likewise, external injuries, gunshot wounds, an auto-erotic accident, suffocation, heat, cold, electricity and lightning and poisons can be the reason why someone is killed. Also conceivable are drowning and death in the water, dying from starvation, killing children at birth and sudden death from natural causes.
The morgue
If possible, the corpse is found where the human died or the body lay, and without delay. In special cases, however, the body is taken to a different location, for example, if it is in the middle of a pedestrian zone or quickly turns into decay at the site.
The doctor now looks for certain signs of death such as brain death, fatal injuries, deathly spots or rigor mortis, or even signs of progressive decay or mummification.
Then he establishes the mode of death, with three categories: natural death, unnatural death and unclear death. He then analyzes the concrete cause of demise.
The doctor removes the body to examine all body parts. It is all about recognizing a non-natural mode of death. If this is obvious, as in the case of a slashed throat or a broken skull, the physician must not change the location of the event.
In this case, the doctor only identifies signs of death, and if they are not clear, he will try to revive the person or person concerned. If he changes the crime scene, he should inform the police.
At the time of the coroner's examination, the deceased or the deceased is closely examined to determine whether a natural or unnatural cause of death exists. (Image: CrimeScene / fotolia.com) The death certificate
When the coroner is over, the doctor fills out a death certificate. The doctor must inform the police in three cases: In case of an unclear death, an unnatural death and if the dead person is unknown. The prosecution then decides whether a judicial autopsy is appropriate, that is, whether another person could have caused the death. A specialist at the Institute of Legal Medicine now carries out his own coroner's examination at the scene of the incident.
The autopsy
The forensic institutes mainly carry out judicial sections - with unclear causes of death, not natural deaths or unknown identity of the corpse. The relatives can not object to a judicial section.
The orthodontist opens the head, abdominal and thoracic cavities. He examines each organ individually for injuries and / or pathological changes. He takes organ samples for histological examinations and body fluids such as blood and urine to detect substances such as alcohol.
When the autopsy is finished, he puts the organs back into the body and closes the body cavities. The competent authority may now release the body for burial.
Determination of the time of death
Determining the time of death is especially important in homicides. The time of the killing is the alleged fact, so it can be seen whether suspects have an alibi, and the deed can be reconstructed.
In the early postmortem phase, this point in time can be recognized, among other things, by how pronounced the corpse spots are, whether the rigor mortis has entered or has resolved, whether the muscles can be excited mechanically or electrically, and how cooled the corpse is.
In later phases after death, it is about how pronounced the late changes of the corpse are and which insects are found in which developmental stages on this.
Deathchill
A new process relies on the temperature. The cooling of the corpse is inserted into the physical laws of heat transfer. In addition to the different body tissues, this procedure also takes into account the clothing and coverage and can be applied to different thermal materials.
The circumstances such as static air, wind or thermal radiation can be simulated, as well as the heat production between the onset of death and the "biological death", ie the death of the last cell in the body.
bloodstains
In violent acts, the examination of blood traces is an excellent means of reconstructing the process. They often decode the location, nature and strength of the use of force. Even more: sometimes they even reveal whether it is a suicide, murder, manslaughter, bodily injury resulting in death or an accident. You can even betray the offender if there is a foreign blood.
In order to reconstruct the sequence of events, experts examine the existing traces of blood at the site of the corpse. (Image: Gina Sanders / fotolia.com) Bloodtrack assessors need systematic training, they visit the crime scene, or they rely on photo documents, and they should know the autopsy report.
Forensic physicians distinguished between dripping blood and blood spatter, exhale tracks, acceleration tracks, skid marks, strokes or contact traces that make a Tatrekonstruktion possible.
X-rays
X-ray examination is essential to detect bone injuries. Radiographs clearly show fractures, joint damage and malpositions of the body axes. The recordings reveal foreign objects, such as a bullet in the body, or a plastic part that seals the trachea.
In the case of a gunshot wound, the course of the projectile can be determined and thus whether the projectile caused the death. X-rays also help to determine the age of the dead, as the condition of various bones reliably betrays their age and gender.
Computed Tomography
Computed tomography complements the X-ray examination because it is particularly good at soft tissue. As a result, the location of an injury can be particularly well recognized and determine the shooting angle in a gunshot injury.
sonography
An ultrasound examines what is hidden in x-rays and computed tomography, namely internal injuries as a result of violence with blunt objects. An ultrasound examination of the soft tissues shows how muscles, tendons, nerves and bones change as a result of injuries. In particular, it indicates internal bleeding. Thus, it often provides the decisive evidence when victims of violence no external injuries are recognizable.
victims of violence
However, not only the dead but also the living are being investigated, especially the victims of violence. In the dead as well as the living, this includes traces of DNA in hair, fibers, foreign bodies, blood and saliva. Infrared photography as evidence is also carried out by forensic institutes.
Legal practitioners have a key role in proving child maltreatment and domestic violence.
gunshot wounds
In the case of gunshot wounds, forensic medicine examines the kinetic energy, speed and mass, shape and deformation of the projectile emitted in the body.
In the case of gunshot wounds, forensics investigates, among other things, the bullet points and the deformation of the projectile. (Image: milankubicka / fotolia.com) Are there bone fragments? Is tissue directly destroyed? Is the temporary wound cavity larger than the firing channel that corresponds to the caliber. If it is a high-speed bullet, death may well be shocked.
Is it a shot, a bullet or a graze?
How was the shooting distance? Is it an absolute close shot with attached weapon, what are the bullet points, such as the smoke height, as the punch mark the gun muzzle? Was it a long shot??
Special shot forms are for example the kroner shot, here burst the skull by explosive effect, or the Rikochett shot, a ricochet with deformed projectile.
The type of gunshot wound helps to detect whether it is an accident, a suicide (typical is a patch shot at an accessible location, this is followed by traces of smoke, blood and tissue on the firing hand), a fake suicide, a negligent homicide, for Example in hunting, manslaughter or murder.
Fernschuss speak in many cases for an intentional killing, as well as several bullet wounds on a corpse.
poisoning
Also documented are poisonings, both in the dead and in the living. These include: drug poisoning, drugs, pesticides, pesticides, alkalis and acids. Furthermore, someone can be poisoned by inorganic toxins, gases, hydrocyanic acid and cyanides, sniffers, plants and food.
The experts assess blood and saliva, urine, hair, stomach contents and body tissue in these cases.
Forensic genetics
Forensic genetics investigates biological traces and assigns them to persons in order to solve serious crimes. Another task is to identify unknown deaths, which is necessary above all for mass disasters, for example in the case of earthquakes, major accidents or terrorist attacks. In addition, a genetic test can prove a biological descent, which can be decisive, for example, in questions of inheritance law.
proof of age
The forensic age estimate is important not only for the identification of corpses, but also for offenders without secure personal data. This applies especially to people whose criminal responsibility is unclear.
In Germany, 14, 18 and 21 years age limits to full criminal responsibility. Forensic doctors, for example, check sexual maturity signs and dental status. They X-ray the upper and lower jaw and examine the eruption and cut-off of the permanent teeth.
There is also a radiological examination of the carpal bones of the left hand and a computed tomography of the joints of the clavicle and sternum.
X-rays of the carpal bones help determine the age (Image: figuren-design.de/fotolia.com) Forensic dental analysis
Dental analysis, ie the combination of forensic medicine and dentistry, is necessary to identify unknown dead, but also to analyze bite marks. The human dentition is as individual as a fingerprint and, moreover, hard to destroy: In a domestic fire, for example, teeth are often the only way to identify a corpse.
The probability of identifying unknown persons with dental analysis is over 90%. Bite marks betray the culprit because of its distinctive teeth. Their position in the jaw, their wear and fillings provide an unmistakable pattern. Bite patterns are particularly typical of sexual offenses and child abuse.
Also bite marks in food give evidence of a culprit. If, for example, saliva remnants (DNA) and fingerprints can be found on a bitten apple, the receipts are complete.
entomology
Forensics examines bodies on earth and rock, blood, sperm, excrement, plant parts or grasses. Then insects come into play. But what does entomology have to do with legal medicine? Quite a bit: The stages of development of insect larvae in the corpse allow conclusions as to how long this body is there.
The criminal biologist Mark Bennecke explains: "Are insects present as a maggot, pup or adult on the body? So you can see how long they have been living there. The calculation models for this are very complex. Sometimes you can calculate the lay time to up to a few hours. Then again, a limitation can only be made for weeks or months. "
This can be especially important for people who are dead longer, because, as Bennecke says: "For a corpse, which is strongly decomposed, fall down the usual forensic parameters such as pupil reaction, excitability of the skeleton, temperature drop or rigor mortis initially. Thus, it is extremely difficult to give concrete information. "
What's more, if larvae are found in a corpse that does not occur under the ecological conditions of the site, this indicates that man died in another place. Forensic entomologists also investigate drugs, medications and poisons in the insects on the corpse. The insects and their larvae pick them up from the body of the dead man.
Forensic outpatient clinic
At the Institute for Legal Medicine in Leipzig there is a forensic ambulance, which offers help for victims of violence. It documents injuries and safely preserves the sample material.
Services are:
1) Free investigation of victims of violence, especially children and adolescents
2) Description and documentation of injuries
3) Reconstruction of the incident that led to the injury, including photos and radiological findings
4) The safe storage of potential evidence
5) Telephone counseling for victims of violence and their relatives
6) Imparting diagnostic and therapeutic measures
7) Advice to doctors
8) Advising youth welfare offices and police on the severity of injuries and recurrence
9) Further education for doctors to recognize violence, as well as youth welfare offices, teachers and educators such as teachers and educators
Forensic medicine is now one of the most important building blocks for clarifying crimes and determining causes of death (Dr Utz Anhalt).
Specialist supervision: Barbara Schindewolf-Lensch (doctor)