godfather of surgery

Chapter 1161 A Clever Method of Committing the Crime

“These blood clots are a mixture of two types of red blood cells. The clot in the middle is one type of red blood cell, while the surrounding red blood cells are another type. The two types of red blood cells do not come from the same person.” Wen Ruzheng finally finished reviewing the footage.

Director Yuan was dumbfounded by his words. How could a blood clot be from two people? How could a blood clot taken from one person's body contain the red blood cells of two people?

"Have you done any genetic testing to verify the identity of this blood clot?" Yang Ping had no doubt about Wen Ruzheng's abilities; the fact that he could say this in this situation meant that he was almost 100% certain.

Dr. Yuan shook his head: "No, for deceased individuals with a known identity, tissue samples taken from their own bodies are generally not used for genetic testing to identify them."

"Professor Yang, could you please take another look? That would be more accurate." The matter was of great importance, and Wen Ruzheng couldn't afford to make a mistake due to his overconfidence. He asked Yang Ping for his help in ensuring the accuracy of the assessment.

Wen Ruzheng gave up his seat. Since the matter was of great importance, Yang Ping decided to help take a closer look at what was going on. He sat down and carefully examined the pathological slide of the thrombus under the microscope. Sure enough, there were two types of red blood cells in the thrombus, and these two types of red blood cells came from different people.

Wen Ruzheng's skill level is truly high. Not to mention ordinary doctors, there are very few pathologists in the world who can see the subtle differences between the normal red blood cells of two different adults. It is perfectly normal that Dr. Yuan cannot see it.

"Dr. Wen is right. This blood clot contains red blood cells from two people. The red blood cells in the central area come from one person, and the red blood cells in the surrounding area come from the other person." Yang Ping affirmed Wen Ruzheng's judgment after reading it.

“This situation is very difficult to judge; even experienced top pathologists cannot tell the difference.” Yang Ping’s words were meant to reassure Dr. Yuan that it was normal for him not to be able to tell the difference.

"In that case, we'll do genetic testing on the thrombus next, so we can finally determine genetically whether it came from two different people?" Dr. Yuan immediately understood what to do next.

However, if this is the case, the situation takes a complete turn. He originally thought the death was caused by illness, but now the blood clot contains the red blood cells of two people, indicating that the blood clot is foreign and comes from another person's blood.

Why would this happen? Could it be that someone injected another person's blood into the deceased's body, causing the foreign blood to coagulate into a blood clot, forming a thrombus that leads to a pulmonary embolism, and then, centered on this thrombus, triggering a thrombus formation process in the deceased's own body?

If that's really the case, the murderer is truly clever and meticulous. If I hadn't been careful and consulted with various parties after noticing something amiss, I would have almost been deceived.

This is a highly intelligent method of murder, and it is of great importance. Dr. Yuan decided to take this opportunity to clarify some clinical professional knowledge, as it would be difficult to have another chance to communicate with Professor Yang face to face in the future.

Sanbo Hospital truly lives up to its reputation; they were even able to detect abnormalities in pathological slides like this.

"Professor Yang, since the pathological slides show that there are two people's red blood cells, what could be the cause from a clinical perspective?" Dr. Yuan asked. He didn't care if he was taking up Professor Yang's time, because if the case wasn't handled properly, it would affect the judgment of the case.

“I don’t understand your forensic medicine knowledge. Everything I’ve said is based solely on judgments derived from basic and clinical medical knowledge. There are only two possible sources of allogeneic red blood cells in the deceased’s body. The first is a medical procedure, namely a blood transfusion. However, normal blood transfusions do not cause the transfused blood to form blood clots, and according to your records, the patient did not receive any blood transfusions. The other possibility is a non-medical procedure, where someone draws blood from another person and injects it into the deceased’s body intravenously. The injected blood has already undergone some kind of treatment and is in a critical state. After injection, it immediately coagulates in the deceased’s blood vessels to form blood clots. These blood clots form free thrombi, which enter the heart through the bloodstream and then the pulmonary circulation. As more blood clots enter the pulmonary circulation, pulmonary embolism eventually forms. These pulmonary embolisms then cause blood clots to form in the body itself, creating a vicious cycle that ultimately leads to fatal pulmonary embolism.”

"In fact, if it is the latter, as long as no foreign red blood cells are found mixed in the blood clot, the autopsy will definitely conclude that the deceased died from his own pulmonary embolism."

"If—and I mean if, this is just speculation—if someone did this intentionally, it would be an extremely clever method of murder."

"What I am about to say is all speculation, for your reference."

“You see, the patient has diabetes and needs to inject insulin subcutaneously into the abdominal wall every day. This is an excellent background to hide the problem. Under such circumstances, it is not surprising that there are a lot of needle holes in the abdominal wall. If it were a healthy person with no history of insulin injection, any needle hole on their body would be a focus of your attention. However, if a patient who needs to inject insulin several times a day has some needle holes in the abdominal wall, and the needle holes are consistent with the insulin injection needle, you will not have any suspicion.”

"Moreover, if the patient died from air embolism, alcohol poisoning, hypoglycemia, or pulmonary embolism caused by the injection of other foreign objects into the body, etc., these would certainly arouse your high suspicion. After rigorous analysis and testing, it would be easy to find the cause of death. However, if the patient died from pulmonary embolism caused by thrombosis, you would certainly not suffer any harm. Everything is too normal, and there is nothing suspicious."

"Even if the flaw is right here, the blood clot contains red blood cells from two different people. This abnormality is not visible under a microscope. Moreover, this is an inevitable loophole in your forensic work process. It's not so much a loophole as exploiting a weakness inherent in your work environment. You might perform genetic testing for identification or trace evidence, but you would never perform genetic analysis on the various tissues taken from an autopsy. You would only perform pathological examinations because these are tissues from the deceased's own body, with no doubts about their identity. How could you possibly perform genetic testing on a piece of tissue from the deceased's own body to confirm whether it came from the deceased? This doesn't align with your work logic."

"I mean, if there is a murderer who is very intelligent and has certain medical and forensic knowledge, or who taught himself certain medical and forensic knowledge in order to commit this crime."

Yang Ping shared his theory, which was already a done deal: the other people's red blood cells in the blood clot were injected intentionally. The only questions were who injected them and why.

As for the final genetic testing results, it is required by the procedure, but the pathological conclusions made by examining the pathological slides under a microscope are now absolutely accurate and without error. This is the gold standard in clinical practice, but it is not necessarily the gold standard in forensic medicine.

After hearing Yang Ping's words, Dr. Yuan suddenly understood and his thinking immediately opened up. He realized that after so many years as a forensic doctor, he had almost capsized in a ditch.

Fortunately, my mentor advised me: Since there are doubts, don't jump to conclusions. Consult with clinical experts to get a clearer understanding.

It seems the saying "better safe than sorry" is true. If I hadn't been careful, I would have died from a pulmonary embolism, and this matter would have been over.

The deceased's family must know something about the case and feel that his lover had a motive for murder, which is why they called the police to request an investigation. However, the family cannot explain why the deceased's lover would commit murder; they are only guessing based on their feelings.

The deceased's lover also felt extremely wronged. She had been taking care of the deceased and actively called 120 for emergency treatment when he fell ill, and she had done nothing wrong.

The deceased had used insulin before his death, but the insulin pen had the deceased's fingerprints, as well as his lover's fingerprints, and actually the fingerprints of other family members.

This isn't surprising; sometimes the deceased injects insulin, and sometimes they ask family members for help, so multiple fingerprints are often found on the body. Did he inject someone else's blood into himself? Why would he do that? The situation is getting increasingly bizarre.

"For such a thrombus to form, it must be left to stand for a few minutes before being injected into the body. This is because there are short, filamentous thrombi accumulating in the middle of the thrombus. These thrombi must have formed immediately after the injection of exogenous blood, indicating that it had already reached the critical point of forming a blood clot while outside the body."

Wen Ruzheng analyzed that he has a very deep understanding of pathology.

"You mean this kind of blood must be drawn on the spot and cannot be left for too long?" Dr. Yuan asked.

Wen Ruzheng nodded: "Judging from this thrombus, the central cluster of red blood cells indicates it's foreign. For this type of thrombus to form, it needs to be injected within minutes of extraction. Too early, and it won't form this filamentous shape. The filamentous shape is actually the shape of the needle, meaning it was already gel-like when injected. Too late, and it has already formed a blood clot, making it impossible to inject through such a fine needle. So, timing is very difficult. Moreover, judging from its morphology, this thrombus likely didn't involve any clotting agents or anticoagulants that interfere with blood clotting. I wonder what your forensic test results are?"

Dr. Yuan was very clear about the details of these tests: "Yes, we tested them, and there were no drugs that interfered with blood clotting."

That makes sense. If that's the case, and if it was done intentionally, the person might have drawn their own blood or the blood of someone close to them. Otherwise, how could it be so convenient? And they would also need to keep it a secret, so the possibility of drawing their own blood is very high.

Oh no, the deceased's lover might be a prime suspect, since the deceased had been with her for over ten hours before her death.

Dr. Yuan reacted quickly. He immediately picked up the phone and called the captain of the criminal investigation team in charge of the case at the municipal bureau, instructing them to immediately apprehend the deceased's lover. They needed to draw her blood for genetic comparison, and the blood samples of the other lovers who were present at the time also had to be taken for testing.

Regardless of whether it is true or not, we must not miss it.

The discovery was truly remarkable. From a single pathology slide, the doctors here were able to identify red blood cells from two different individuals. If word got out today, the forensic community would be abuzz with the incredible story of solving a bizarre case with just a pathology slide.

Does this person have some medical knowledge? Dr. Yuan remembered that he had seen the investigation files of this case and the basic information of the people around the deceased. Among them, his lover had studied medicine before. As long as a person who has studied medicine is willing, it is not difficult to master this knowledge. In addition, it is not difficult to master some forensic knowledge and understand the forensic work process.

Could it really be as the two doctors said? If so, this is a murder case, an extremely clever and well-hidden murder case, where the cause of death is carefully disguised as death from illness.

Actually, Dr. Yuan has seen cases like this before, but the disguises were clumsy and not so sophisticated, making them easy to spot.

Dr. Yuan racked his brains, trying to think of any other questions he could ask. He didn't care about saving face or revealing any academic weaknesses. In fact, as a true scholar, one should know what one knows and admit what one doesn't know. What does saving face have to do with anything?

"Professor Yang, I have another question. I'm really sorry to have taken up so much of your time." Dr. Yuan felt quite apologetic.

Yang Ping said, "It's alright, please go ahead."

"Can an insulin pen be used directly for drawing blood like a regular syringe?" Dr. Yuan asked. Actually, he could have drawn a conclusion simply by having the insulin pen analyzed by the lab technicians, but he wanted to find out for sure.

Yang Ping thought for a moment and said, "Our nurses are probably more qualified to answer this question; they understand the structure of insulin pens better than we do."

Director Zhao immediately picked up the phone and called the endocrinology department, asking them to send a senior nurse.

"I have one more question. I'm sorry, I might have a lot of questions."

Dr. Yuan said embarrassedly,

"If this blood was injected through a vein in the abdominal wall, would there be any traces left around the injection site? For example, detectable leaked or residual red blood cells?"

The main reason for asking this question was to accumulate experience for himself; Dr. Yuan wanted to delve deeper into the experiential value of the information from this case.

"There will definitely be some hemolytic reactions. If the blood type is wrong, it will actually cause some hemolytic reactions. No matter how severe the reaction is, there will definitely be some hemolytic reactions."

Dr. Yuan nodded, as if he had thought of something else.

They also tested the insulin pen at the time. It contained insulin, and the dosage matched the deceased's usage schedule. The pen had the deceased's fingerprints on it, as well as his lover's fingerprints. Since the deceased sometimes needed his lover to help inject insulin, this could be explained, and the explanation was quite reasonable.

If blood was injected using an insulin pen, there should be residue in it. Of course, the murderer wouldn't leave such obvious evidence for the police.

Therefore, it's possible that the blood wasn't injected using the insulin pen, but rather another tool that has been destroyed or hidden.

Is it possible that the murderer secretly switched the insulin pen used by the victim with the same tool, and then the victim had his lover inject the insulin? The lover then skillfully performed a superficial venous puncture in the abdominal wall, injecting blood into his body, causing a blood clot, and leading to a fatal pulmonary embolism.

To find out the truth, we can only wait for the next step of inspection and investigation.