It is said that the most important thing in western detective work is reading. When talking to each other, you must listen to the clues of things, otherwise you will lose your qualification as a detective.
To master interpretation, you must do the following:
1 First of all, in order to gain the trust of the other party, talk to the other party politely.
It's better to talk than to listen.
If there are cats or dogs in the other person's house, don't let them go. Because cats and dogs will say what their owners say.
It is important to ask the same question skillfully in different ways after two questions. Confirm the facts.
5 in front of your opponent, you can't take out a note to make a record, which will alert the other party. So, just ask orally and keep what the other person said in mind.
If you seem to have forgotten everything, put your hands in your pockets and learn the skills of making memos.
Even if the other person complains, or talks about his own life experience and situation, as a relative, he should take pains to listen.
8 Cooperate with the other person's personality and change the conversation skills.
Second, the inference of time and cause 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 it will 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.
Suicide is when a gun is pointed at the head, which will leave hot marks around the bullet hole and the color of the surrounding skin will deepen. Besides, the hole the bullet enters is smaller than the hole it exits, and there is less blood flow. ※. Under normal circumstances, only suicide will leave burn marks.
If the lungs are perforated, even if you want to breathe, you can't breathe smoothly because the lungs can't expand, which will lead to suffocation and death. You can probably struggle painfully before you die 10~ 15 points. ※.
Drowning: slight water stains in the mouth, dilated pupils, bleeding on the mucous membrane of the eyes, and rupture of the eardrum due to water pressure, leading to bleeding. ※.
Poisoning: the lips turn purple or black first, and then other parts of the body will also appear this phenomenon. Sometimes eyes stare, hands clench fists, waist and legs curl up, etc. ※.
Choke to death: there is a deep purple imprint on the throat. When it hurts, the pupil expands and the tongue sometimes sticks out, showing purple-black. ※.
Cleaning the wound with tea to neutralize toxicity is the best way to deal with sea snake bites, because tannins contained in tea can detoxify. In addition, the person in charge of sucking out the poison should also gargle with tea to prevent poisoning. ※.
In case of food poisoning, mung beans can be ground and washed to temporarily remove toxicity. ※.
When salt is mixed with acidic detergent, it will produce toxic gas. ※.
The skin of the deceased was pink with some spots from the inside out, which was obviously caused by sodium hydroxide poisoning. If the poison be 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. Thank you for your correction in this article! )
The surgeon will leave a deep and obvious mark on his index finger, which is caused by frequent dressing. ※.
The hair of the deceased was slightly burnt and the muscles of the whole body were extremely stiff, which was the characteristic of high-voltage electric death. ※.
The scald caused by the current flowing into the body from the fingertips will turn the fingers gray. ※.
Eating potassium hydroxide may lead to suffocation and death (potassium hydroxide has almond flavor). ※.
If you poison a flower, the flower itself should wither first. ※.
On the surface, it seems that it is a "suicide" death by biting the tongue, and sometimes it is a convulsion caused by inhaling poisonous gas or swallowing poison. ※.
There are many kinds of poisonous bacteria, some of which release poisonous toxins. Poisonous bacteria can also be used as medicine, but they are also poisonous, so you'd better not eat them. ※.
Carbon dioxide poisoning: the gas around people contains more than 20% carbon dioxide, so people will have severe convulsions after inhalation, and they will bite their tongues in a few seconds and die of cold. Carbon dioxide is heavier than air, so it will sink in a certain space. ※.
If the spasm is caused by massive bleeding, a rope must be tied around the wound to stop bleeding and prevent excessive bleeding. Next, massage your heart. ※.
If a person's internal organs are broken, there will be a special smell of internal organs. ※.
A big echo in the cave means there is no road, and a small echo means there is still a road. ※.
Sodium sulfide (bleach) can detoxify potassium hydroxide. ※.
The surface of pearl is calcium carbonate, which is most afraid of acid corrosion. Therefore, when touching precious pearls, be sure to wear gloves or wrap them with handkerchiefs. If you don't use them, pearls will come into contact with oil stains on your hands, and the luster of pearls will disappear faster. The luster life of pearl surface is 30~40 years at most, and then it will fade slowly. ※.
When the corpse is buried 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 water. ※.
Generally, people who have been missing for more than seven years will be confirmed dead, and those who have disappeared due to natural disasters or disasters will be confirmed dead for more than one year. ※.
Third, fingerprints
Fingerprints can be divided into three categories:
The first is obvious lines, which are visible to the naked eye. Such as hand-dyed paint, blood, ink and other articles for transfer printing.
Generally, it is printed on the fingerprint card to become the basic information;
The second type is molded patterns, which refer to fingerprints found on soft substances, such as candles and clay.
The third kind is latent fingerprint, which is the fingerprint pattern formed by the transfer of human natural secretions such as sweat.
It is not easy to find by visual inspection, and it is the most common fingerprint at the crime scene. Latent fingerprints are often when fingers first come into contact with grease and sweat.
Liquid or dust, and then contact with a clean surface and leave, although these fingerprints are invisible to the naked eye, but after a special
Other methods and the use of some special chemical reagents can show these potential fingerprints.
The most common fingerprint that forensic doctors come into contact with is latent fingerprint. If fingerprints are left on metal, plastic,
It is easier to test the surfaces of non-absorbent articles such as glass and tiles. Usually, it can be selected by powder method.
Sprinkle powder with large color contrast on the surface of the object to extract a complete fingerprint; Another method is magnetic powder method, which uses fine particles.
Iron powder particles, using a magnet as a brush, brush back and forth to show fingerprints.
If fingerprints are left on the surface of absorbent articles such as paper, cards, leather and wood, they must be chemically treated.
In the lab. Commonly used chemical methods are:
Iodine fumigation-that is, iodine crystals are heated to produce steam, which reacts with the grease left in fingerprints, and then
Yellow-brown fingerprints will appear and must be photographed immediately or fixed by chemical methods;
Ninhydrin method-spray the reagent on the sample, and the reagent will react with the amino acids in the body secretion.
A purple fingerprint will appear after the response;
Silver nitrate method-after the silver nitrate solution reacts with the sodium amino in the latent fingerprint, it will produce black in the sun.
Color fingerprint;
Fluorescent reagent method-Fluorescent ammonia and phthalaldehyde react with protein or amino acid of fingerprint residue almost immediately,
High fluorescence fingerprint are generated, and that reagent can be use on the surface of colored articles.
Other methods can also be used to collect evidence, such as three-second glue method, that is, cyanoacrylate gas is mixed with water.
Amino acid molecules react to produce fingerprints.
Fourth, the preliminary inference of the time of death
Corneal opacity unit: hours
Mild 12
Medium 24
Height 48
Corpse ecchymosis
0.5- 1
Mild 2-3
Moderate 4-5
dead body
Start 2-3
Stiff whole body 4-7
Strongest 12
Body cooling (2 1℃) unit: hour.
37 (in degrees Celsius) 1
37 2
36.5 3
35.5 4
34 5
33 6
32 7
3 1 8
30.5 9
29.5 10
28.5 1 1
Within an hour, the body had no lividity and rigor mortis.
Mild lividity and rigor mortis appeared in the neck within 2-3 hours.
The lividity changes obviously, the lividity can subside, and the rigor mortis stops in the upper limbs within 4-5 hours.
Stiff dead spots are obvious and will not disappear in 7-8 hours.
Typing is tiring. Give me some advice.