Chapter 13 cat testimony

Prince Edward Island is located between 46° and 47° north latitude and 62° and 64° 30′ west longitude.It is about 209 kilometers long and 6.4 to 54 kilometers wide. It is known as the "Gulf of St. Lawrence Park".The coast is winding and deep, with many fjords and large harbors.The whole island constitutes a province of Canada, the provincial capital Charlottetown, located on the north shore of Hillsborough Bay.And I work for the Charlottetown Police Department, specializing in DNA analysis verification. Compared with other colleagues in the police station, my job is relatively easy. If it is not a particularly important case, I generally do not go to the scene to collect evidence.I usually stay in the lab or office when other colleagues are on the go.So, on the afternoon of October 7th, when I saw Detective Witt walking towards my office, I knew that something serious must have happened again.

"Just now, a woman called us and said that an abandoned car appeared in the wilderness near her home. There was a lot of blood in the car. She didn't dare to continue to check. Maybe it was another murder..." Before Werther finished speaking, I stood up.After staying in the office for too long, I think I should also go out for some air. By the time I got to the field where the incident happened, other people were already at work, and they were asking the woman who reported how she found the car that had been left in the field, and making sure that no one had been there since she called At the scene, no one has touched any items.

"Marilyn, there are some blood stains in the car. I need you to go there and check carefully, and then tell me how you can make them speak. Let's go to other places to look." After Inspector Witt ordered me, he took several agents towards Go to another place.I know that they started to delineate the scope of investigation, and they will patrol around the crime scene by the way.The reason for delineating the scope of investigation is mainly to grasp the key points of the case.Because the scene conditions of various cases are different, we need to delineate according to the specific environment and conditions. Generally, the scene should include the place where the case occurred, and the place where there are traces and physical evidence related to the crime.The place where the case occurs is the place of the crime, for example: the place of murder and the place of theft are the places of crime.However, in addition to these places, criminals still have a problem with the route of coming and going, the places where all the remaining evidence such as moving, hiding stolen goods and abandoning murder weapons, and burying corpses and so on, all of which should be included in the scope of our investigation.Sometimes, the place where we find the victim's body is not necessarily the place where the murder was committed. We have encountered this situation more than once.Therefore, we must not only investigate the location where the body was found, but also find out the real location of the killing and other places where the body was moved.

However, that's not what I'm doing right now.After they were far away, I took the toolbox and came to the car.I looked into the car and saw that there were large bloodstains on the seats in the car, and there were blood drops on the windshield, the inner side of the car, and the side windows of the car, which proved that there had been bloodshed in the car. I began to carefully observe the blood droplets on the car window. From my many years of experience, I can conclude that the blood droplets are sprayed by people after a moderate impact. At that time, the people in the car should have been attacked by an object similar to a fist. .

Here, I want to popularize a little blood knowledge first.You should know that blood is not a single component. It is composed of plasma and blood cells. Plasma contains water, low molecular substances, protein, oxygen, carbon dioxide, etc., while blood cells contain white blood cells, red blood cells and platelets.Someone asked, how long does it take for human blood to coagulate?For this question, it should be said that if the time of death is judged according to the coagulation state of the blood, it should be 2 to 4 minutes. Yes, it's 3 minutes. You don't need to worry about the coagulation state, just look at the blood color.The darker and deeper the blood, the longer the death time. If the blood is yellow, it means that the person has been dead for a long time.Blood has its own coagulation mechanism, but it has no coagulation point. If they just flow in the blood, they will not coagulate, and the blood flowing out of the body will coagulate under the action of platelets, but the coagulation time varies from person to person, external conditions The difference also affects blood clotting.If we use the glass slide method, after 2 to 8 minutes, we will see blood coagulation.

In addition, after the death of an ordinary person, the blood in the whole body will coagulate within 6 to 10 hours, but there are many factors that affect blood coagulation. The difference in solidification time depends on the local temperature, wind speed and other conditions. Prince Edward Island is Canada's smallest province, covering an area of ​​2,100 square miles, sheltered from the heat in summer and cold and desolate in winter.There are six climate zones across Canada, namely: the coldest part of Canada is in the Northwest, which belongs to the Arctic region; and the second northern region refers to the northern part of the prairie provinces, such as Ontario and Quebec, where winter is long and summer Short, four distinct seasons, moderate rainfall; the third is the prairie region, cold in winter, cool in summer, spring and autumn are not very clear, most of the rainfall in summer; the fourth is the Canadian mountain region, the weather is changeable, most of the time is wind There is heavy snow, and the temperature will drop sharply as the terrain increases; the Pacific coast of Canada belongs to the fifth climate zone, such as Vancouver, which has a pleasant climate and is the most suitable for living.

Prince Edward Island, where our case took place, belongs to Canada's sixth climatic characteristic zone. Every year here, winter is long and summer is short. July and August here are considered summer, and the arrival of winter is the first frost. The night is used as the boundary, which is usually on a certain day in mid-September. It is now the first ten days of October. If this is inferred, then the murder occurred in winter.Because here from September to October, the trees have already begun to shed their leaves, and in the following November and December, we can see heavy snow all over the sky, and this snow scene will continue until March of the next year.

Human blood is usually red or dark red, but the color of the bloodstains at the crime scene also shows different colors in different places.In this jungle, the leaves are sparse, and a little sunlight passes through the gaps in the trees, allowing me to see the difference between the blood stains in the car and the blood stains left on the side window of the car.Some bloodstains have been stimulated by light and changes in temperature, and their color has also changed accordingly. The bloodstains will be affected by the early winter air here, and will dry out and turn dark red.This is the case with the blood in the car and the blood on the side windows.

The side windows of the car belong to light-colored glass, and the blood stains left on such light-colored objects are more obvious.When I was investigating the case, I paid great attention to observing the color of the original blood stain.But I found that the color of the bloodstain on the steering wheel in the car is a bit darker. This is because the original object with the bloodstain is darker, and it is not easy to observe the bloodstain left on this object. Checking here, how I wish the sun could shine through the gaps in the trees, if so, I can check more clearly.The case did not necessarily happen during the day, or on a sunny day. In other cases, I held a flashlight more often at night or in the middle of the night, and used the method of oblique light inspection to check the blood stains. Where there is light, there may be blood.Sometimes, I also use ultraviolet light to check for blood stains, and if there is blood, I will see a dusty brown fluorescent.

We all know that fresh blood is bright red, and old blood stains will turn grayish brown once they are warmed.If it is a rotten blood spot, it will turn light green, and if it is under humid conditions, the rotten bloodstain will turn dirty green. Next, I started looking for spots of blood that had fallen on various surfaces around the car.These bloodstains also have different shapes. If it is an injured person, the bloodstain dripped by this person during the journey is in the shape of an ellipse. At this time, pay attention to the end with the starburst, that is the direction in which the injured person is traveling.For example, arterial bleeding appears in the shape of an exclamation mark, and its tip is the direction in which the blood is sprayed out.If it is wiped blood, its area is generally larger, and the shade is uneven, accompanied by rubbing lines.

I also found some suspicious blood spots around the car, I put a solution of aniline glacial acetic acid on those spots, if they turn blue, that's probably blood too.I also found some rocks and sticks.I circled around the grass and leaves, carefully observing their surfaces, and sometimes the criminals left blood on these objects.But in any case, it would be even better to find the original bloodstain, and I look forward to this discovery. The next thing to do is to take blood samples. After taking pictures of various parts of the car, I scraped off a blood stain with a clean knife and put it on a clean piece of paper.Of course, there is another method when collecting blood samples. Use damp cotton gauze or clean cotton to absorb the blood on the original object, and then dry it indoors. I could see that the blood drops of the deceased were ejected from a moderate impact in life.Rapid bleeding is characterized by a thin, long straight line, while slow bleeding is a short, thick, curved line that shows coagulation.This allows you to see the direction of the blood flow based on the traces of the blood flow.Generally, the blood dripping down from a height of one meter has a jagged shape around the bloodstain, while the blood dripping down from a height of one to three meters has a linear shape around the bloodstain.The blood spurted out by the deceased during his lifetime is a state characterized by rapid bleeding. The bloodstain issue became clearer. Before Werther and the others came back, I sat down by the car and imagined some details of the victim's injuries in my mind.I already knew from the bloodstains that the victim had been hit with something like a fist.In homicide cases, the head is often the main target of criminals.Skull fractures occur when mechanical forces exceed the elastic resistance of the skull.Fractures can be divided into linear fractures, depressed fractures, hole fractures and comminuted fractures.In the linear fracture of the skull, linear cracks may appear, and the skull is broken, but the local bone has no depression and significant displacement, and the cracks are also small. The fractures are mostly formed by small blunt round injuries.Assuming that the blunt force blow caused by the collapse of the skull bone is damaged, it is a depressed fracture.In the deepest part of the depression, it can be seen that it is often consistent with the most prominent part of the contact surface of the blunt instrument. This kind of fracture is usually formed by irregular edges or spherical blunt instruments under the impact of large mechanical force and fast speed. of.However, the depressed bone plate is not separated from the surrounding area, and ring-shaped bone cracks are often formed around the fracture area.A hole fracture occurs when a blunt instrument strikes the skull violently, causing a defect at the fracture site and causing a piece of bone to sink into the cranial cavity.This kind of fracture is mostly formed by a blunt instrument with small contact surface or protruding edges and corners under the impact of high force and fast speed.Fracture morphology can usually reflect the type of injury.For example, the hole-shaped fracture formed by hitting the head with the back of the ax and the hammer surface can reflect the shape of the back of the ax and the surface of the hammer.In addition, bullets and sharp objects can also form such fractures.Comminuted fractures can be formed if the contact area of ​​the wounded object is large or the skull is repeatedly hit by a blunt instrument.In the strike zone, the fracture lines intersect and there are multiple fracture fragments.Fragments of broken bones can become embedded in brain tissue or subcutaneous tissue. At the same time, severe blunt force blows are also likely to cause the victim's hedging craniocerebral injury. At this time, the victim's right forehead and right parietotemporal part to the occipital subcutaneous bleeding will be extensive, and the left frontal and parietal lobe subarachnoid hemorrhage , left temporal lobe subarachnoid hemorrhage and cortical contusion, left temporal lobe posterior cortical contusion, extensive cerebral congestion and edema, etc. In severe cases, the victim may faint on the spot. When the victim is in a coma and has no chance to resist, the criminal The victim will be picked up and transferred to any place. I was so absorbed in my own thoughts that I didn't notice that Werther and the others had completed other searches until he slapped me out of my thoughts.It seems that they have gained a lot. Witt told me that the serial number of the car has also indicated the identity of the owner. She is a local woman named Shirley Dugay, 32 years old this year. However, the search did not stop. We continued to search around the scene. One difficulty for us at present is that Shirley Dugay or her body have not been found.In other cases, criminals tend to bury stolen goods or bodies at the scene. Witt also found Shirley's seat cushion near the car, which was soaked in blood. This evidence is very important to me.I suspect that the blood in the car is Shelly's, but to be sure, I need to get a blood sample from Shelly's father, Melvin, for a DNA test.After investigation, Shirley has five children, the oldest one is fifteen years old, and the youngest is a pair of eight-year-old twins.Shirley disappeared four days ago, and Shirley's father has been taking care of her children these days. The family used to live in a small building in the small town of Richmond, Prince Edward Island, which is now abandoned.