(A) analysis of the cause of death
After finding the body, three questions must be answered: the identity of the deceased, the time of death and the weapon.
Burn sb.
Get an electric shock
The deceased's hair was slightly burnt and his muscles were extremely stiff, which was the characteristic of electrocution under high pressure.
The scald caused by the current flowing into the body from the fingertips will turn the fingers gray.
shoot dead
submerge
Kill with poison
The skin of the deceased was pink with some spots from the inside out, which was obviously caused by sodium hydroxide (NaOH) poisoning. If the poison is in the capsule. It takes at least 15 minutes to show toxicity. It is best to gargle with something containing protein, such as milk. PS: Potassium cyanate is insoluble in cold water.
Eating potassium hydroxide may lead to suffocation and death (potassium hydroxide has almond flavor).
If you poison the flowers, they should wither first. Neurotoxins do not have this effect.
On the surface, it seems that it is a "suicide" death by biting the tongue, and sometimes it is a convulsion caused by inhaling toxic gases or storing poisons.
There are many kinds of Agaricus, some of which emit toxic toxins. Poisonous bacteria can also be used as medicine, but they are also poisonous. It is best not to eat them.
Carbon dioxide poisoning: the gas around people contains more than 20% carbon dioxide, so after inhalation, they will twitch violently, bite their tongues, die a few seconds later, and their bodies will be cold. Carbon dioxide is heavier than air, so it will sink in a certain space.
Sodium sulfide (bleach) can detoxify potassium hydroxide.
Eating a certain amount of sodium nitrite will also kill people. Acute poisoning has only a small amount of toxicity entering the bone marrow.
After organophosphorus poisoning, the pupil will shrink before death, and this sign still exists after death.
Fall to death
commit suicide
Suicide is when a gun is pointed at your head, which will leave hot marks around the bomb and the color of the surrounding skin will deepen. Moreover, the hole in which the bullet enters is smaller than the hole out, and there is less blood flow. Under normal circumstances, only suicide will leave burn marks.
strangle
There are obvious deep purple marks on the throat, the pupils are dilated and painful, and the tongue sometimes sticks out and turns purple-black.
Upper and lower lip mucosal bleeding, neck epidermis peeling, skin flaky bleeding, conjunctival bleeding, etc. Indicates the process of strangulation.
If the deceased was strangled and hit on the head with a blunt instrument, it would cause serious intracranial injury and respiratory failure and die.
The mood before death
If the lungs are perforated, even if you want to breathe, you can't breathe smoothly because the lungs can't expand, which will cause suffocation and death. die
I can probably struggle before 10~ 15.
Drowning: There are slight water stains in the mouth, dilated pupils, bleeding on the eye mucosa, and the eardrum will also rupture due to water pressure.
Cracking leads to bleeding.
Poisoning: the lips first appear purplish or black, and then other parts of the body will also appear this phenomenon; Eyes sometimes stare.
Hands clenched, waist and legs curled, etc.
Choke to death: there is a deep purple mark on the throat, the pupil is dilated and painful, and the tongue sometimes sticks out and is purple.
Black.
When salt is mixed with acidic detergent, it will produce toxic gas.
If a person's internal organs are broken, there will be a special smell of internal organs.
(2) Death weapon
Hitting a person's head with a blunt instrument may even cause a file tear. Usually, there will be no blood spilling from the first blow, but there will be scars around the wound. Only when the second blow is in the same place will the blood come out.
The size of the bullet hole is used to estimate the shooting distance, and the smaller the entrance, the closer it is. It depends on different types of guns and bullets.
(3) Recognition
occupation
The surgeon will leave a deep and obvious mark on his index finger, which is caused by frequent dressing.
Anyone who fishes at sea for a living has his toes separated "-only when his toes are separated can he gain a foothold on a swaying fishing boat.
age
Juvenile criminals have small steps, thin footprints, irregular footprints and winding paths.
Young criminals often have big footprints, big steps, even footprints and walk in a straight line.
Middle-aged criminals walk steadily and slowly, and the distance between footprints becomes shorter. The stride of the elderly criminals is shorter, and the pressure on the heel is heavier than that on the sole of the foot.
Footprints are deep in the heel and shallow in the forefoot, indicating that people who walk stand tall and abdomen, and their bodies are relatively straight.
"If a man can stride four and a half feet effortlessly, he will never be an old man." A study of scarlet letters-Detective Sherlock Holmes
The cusp began to wear, about 13 ~ 23 years old.
Tooth tip is worn, revealing black spots (tooth particles), about 24 ~ 35 years old.
A large area of exposed dentin, about 36 ~ 55 years old.
Dentin is completely exposed, and the tooth cavity can be seen, probably over 56 years old.
Age can also be judged by the growth of teeth. For example, deciduous teeth usually grow out in about 6 months, and they are 20 at the age of 2. At the age of 7 to 8, teeth began to change, and the left and right upper and lower first molars began to grow. 1 1 year old, all deciduous teeth are replaced by permanent teeth. Before 16 years old, the second molar began to grow. He is about 25 years old and has a third molar (wisdom tooth).
Author: 222.248. 137. Reply to this statement.
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2 [Recommended] Basic reasoning knowledge (80% required)
height
Height (cm) = Footprint length (cm) ×6.876
"Nine times out of ten, a person's height can be known from the length of his steps." A study of scarlet letters-Detective Sherlock Holmes
Femoral length = (height-61.7207 2.1756) ÷ 2.4378
Leg bone length = (height-54.25221.9214) ÷1.4294-(thigh bone length)
Humeral length = (height-81.5155 2.8903) ÷ 2.438+031.
weight
Generally speaking, the bone surface of fat people is smooth, while that of thin people is rough.
gender
Generally speaking, the bones of men are heavy and thick, while those of women are light and thin.
health
The chaotic pace and uneven distance between footprints indicate that criminals may be exhausted or injured.
The high cadmium content in hair indicates that this person is a heavy smoker.
The content of chromium in hair of children with polyuria is low.
The contents of cadmium and manganese in the hair of schizophrenic patients are very low, while the contents of aluminum and iron are very high.
Malnourished children have low zinc content in their hair.
facial characteristic
The skull is very smooth, indicating that it was fat before death; The width of the mouth is equivalent to the width between the left and right second premolars; Maxillary alveolar process shows that the deceased's lips were thick before his death; The length of the ear is almost equal to the length of the nose, and the width is exactly half of the length.
If each toe is far away, this person is often barefoot. -Sherlock Holmes
(4) Time of death
People generally become stiff within 30 minutes to 2 hours after death, and will become stiff after 9 to 12 hours. After 30 hours, it will continue to be stiff, then soften and return to its original state in about 70 hours. Usually, this is the case, but if the ambient temperature is higher than 35 degrees, the stiffness and softening will accelerate and it will recover in 24 hours. After strenuous exercise before death, protein is easy to solidify in the body, and will become stiff faster than usual after death.
Burying a corpse in the soil, so that the corpse can't touch the air, the decomposition speed of the corpse will be normal 1/8, and it will be slower in the water.
People who have been missing for more than seven years are generally confirmed dead. People are missing due to natural disasters or disasters, and their death is confirmed to be more than 1 year.
If there is strenuous exercise before death, it will generally have little effect on rigor mortis, usually 1-2 hours, but it will have a great effect on tissue autolysis. The tissue autolysis rate of strenuous exercise will be much faster than that of non-strenuous exercise.
How to determine the stage of rigor mortis?
The general order of the occurrence and development of rigor mortis is: head and face > body > limbs, and after the whole body is stiff, it is relieved in the order of head > feet. If you find that your neck is soft now, but your limbs are still stiff, it means that you have entered the remission period. In other cases, it can be analogized. .
1, early postmortem phenomenon
(1) The corpse is fresh, the cornea is transparent, and no lividity and rigor mortis are found-1hour;
(2) The lividity is shallow, and the lividity fades when pressed with fingers; Stiffness only occurs in the jaw and neck joints-2-3 hours;
(3) The rigor mortis extends to the upper limbs and can be reproduced after artificial destruction; When the body position is changed, the original corpse spot fades, and the new lower part appears corpse spot; Sometimes white spots can be seen on the cornea-4-5 hours;
(4) The dead point can't be eliminated by finger pressing, and the original dead point can't be eliminated by changing the body position, and the new lower dead point is not obvious; A stiff corpse; Corneal opacity-7-8 hours;
(5) Lividity has entered the stage of diffusion and fixation; Rigor has developed to the whole body-10 ~12 hours;
(6) The right lower abdominal wall is blue and purple; Stiffness began to ease ――24 hours;
(7) Lower limb stiffness was relieved, and the cornea was completely turbid ――48h；;
(8) the giant concept-2 ~ 4 days.
2. Body temperature
(1) After death 10 hour, the temperature drops every hour1℃;
(2) After death 10 hour, the temperature drops by 0.5℃ per hour.
3. Late death phenomenon
(1) Adult mummification (mummification)-about 3 months.
(2) The bones of corpses on the ground-several months to 1 year;
(3) The soft tissue of the corpse disappears completely ―― 3-5 years;
(4) Dead bodies in the soil have become bones-3-5 years;
(5) Simple bone-10 ~15 years.
Why do bodies have maggots?
Question: Why do maggots grow after a corpse decays? Is it really born from the human body?
A: The maggots found on the corpse were not "born" from human tissues. So maggots are often found on corpses, because the smell of corpses will attract flies to gather on corpses shortly after death. The gathered flies will lay eggs on the corpse, and after a period of time, these eggs will develop into maggots.
In the season with flies, flies lay eggs in the mouth, nose, eyes, external auditory canal, anus and vulva of the deceased shortly after death, and each fly lays eggs once 150. At 30℃, it can hatch into maggots after 8 ~ 14 hours. When the weather is hot, maggots grow about 0.24~0.30cm every day, and when they grow to 1.2cm, they sneak into the nearby soil and become pupae, and they break their shells and become flies in a week or so. In spring and autumn, maggots grow 0. 1cm every day, and it takes about 12 days to become pupae, and then it takes 2 weeks to become flies. Flies can lay eggs in two weeks. In hot weather, the pupa shell was seen next to the body, so it can be said that the body was exposed for at least 2 weeks; Spring and autumn exposure for 4 weeks.
Author: 222.248. 137. Reply to this statement.
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4 [Recommended] Basic reasoning knowledge (80% required)
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Breathing and vomiting have special odor Garlic odor: inorganic phosphorus, organic phosphorus.
Sulfur odor: sulfur-containing compounds
Almond flavor: contains cyanosides and cyanic acid.
Smell: kerosene, alcohol, carbonic acid, coal phenol, tobacco, organic chlorine, acetone, etc.
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Drooling, sweating, organophosphorus, poisonous mushrooms, arsenic, mercury, wild celery, 666, chlordane, salicylate.
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Dry mouth, no sweat, atropine
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Lips and cheeks are cherry red, carbon monoxide, cyanide and so on.
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Face and skin flush atropine, alcohol, nicotinic acid, thyroxine, etc.
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Dyspnea without obvious cyanosis carbon monoxide, cyanosides and cyanic acid, arsenic and mercury.
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Purple skin has no dyspnea, nitrite, pyrazolone, aniline, iodoamine, and contains sulfide.
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Auditory hallucination, delirium, atropine, chlorpromazine, promethazine, poisonous mushrooms, alcohol, marijuana.
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Pupil contraction anesthetic organophosphorus poisonous mushrooms
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Atropine, amphetamines, barbiturates, cocaine, methanol
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Blind methanol quinine
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║ color vision ║ mountain road year, digitalis ║.
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Muscle tremor, convulsion, organophosphorus, DDT, chlordane, nicotine, barium and mercury.
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Botulinum botulinum muscle paralysis, puffer fish, snake venom, wild celery
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Urine green-blue-methylene blue, phenol, sallow
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