"It's actually not difficult," said Holmes. "To be honest, I thought I had encountered some rare and strange case when I heard Grigson's words, at least the kind that happened on the Isle of Allen in 1832. But after I went to the scene and found that it was nothing great. Let's talk about John Textile Factory first."

Sherlock Holmes paused, “Do you remember what we had during our afternoon chat?”

"Are you talking about the impact of professional opponents?"

"Yes, I have been doing research on this area recently. I have found many people from all walks of life in London, including bricklayers, fishermen, cooks, typists, etc.... I go out every morning just dawn and stay in the slums until the sun sets. I spend a lot of time studying their hand shapes, comparing each other and comparing them with others in the same industry. The results are significant. I am planning to organize it into a paper," said Sherlock Holmes. "Just just by the river, I focused on checking the child's palms and comparing her palms with my research results. Although her body has been soaked in the water for quite some time, there is no doubt that she works in a textile factory, so your previous observation is not a problem, because long-term work makes her body a little weak, and she is probably still sick at the time of the incident."

"But there are many textile mills in London, why can you be sure which John textile mill she is in?"

"Good question," said Holmes, "I tend to think that the place where the abandoned corpse is very close and the place where the corpse is found is very easy to explain. The time for the corpse is found during the day. Although there is a little fog on the river, the visibility is actually quite good. In addition, there are cruise ships or cargo ships passing by from time to time. If there are corpses on the river, it is difficult to float too far away to be discovered."

"Wait, but you said that her body had been soaked in the water for quite some time."

"Yes," Sherlock Holmes smiled sly, "but please pay attention to my words. I mean that her body was soaked in the water for quite some time, rather than drifting for quite some time."

“Is there any difference between the two?”

"Of course, judging from the state of the corpse, the victim's death should be the time when the perpetrator accidentally killed her last night. After that, he threw the corpse into the river and had stones tied up, so that it would not be discovered. People only think that the child is missing. People are unable to survive in this city every day, especially for the lower class like her, there are not many people who care about where she has gone. You should know that the police station's attitude towards disappearance and murder is completely different."

"Then why was her body discovered by the patrol again?"

"There are many possibilities. Maybe the person who committed the crime was too nervous and did not tie the rope. Maybe something happened to pass and broke the rope..." Sherlock Holmes said, "I am not a fool. In addition to the time issue I mentioned, I did find traces of being tied up by the rope on the victim's wrist. In this way, things can be explained. Her body was soaked in the water for a long time, but it didn't take long to get out of the trap and float to the place where she was found."

"John Textile Factory is the closest textile factory here in Shangyou, and it is also the place I doubted the first. In addition, I found some blue crystals in her hair, which are copper sulfate pentahydrate formed after copper sulfate was exposed to water. Coincidentally, next door to John Textile Factory happens to be a chemical factory, which is also the most important basis for me to make the final inference." Sherlock Holmes said.

"It is better to see it at first sight than to hear it. This has already improved criminal investigation to a level of nearly precision science." Zhang Heng also exclaimed sincerely.

Although Sherlock Holmes heard the praise, his expression seemed very useful, and paused and continued, "As for the inferences about the assaulter, it's nothing great to say."

"I hope to hear the details."

"We all know that the perpetrator wants to take advantage of the victim, but was strongly resisted by the child. She was very brave and kept fighting with the other party. However, the difference in strength between the two parties was too obvious, so she still couldn't escape in the end. However, the guy didn't feel comfortable for too long and was caught by the victim's skin. Although the body had been soaked in the water for a long time, there was still some skin tissue left in the cracks of his nails. This was probably the reason why he was angry and strangled her to death in anger."

"Wait...you said your child was strangled to death?"

"That's right." Sherlock Holmes said very surely.

"But hasn't she been hit hard on the head?" Zhang Heng asked.

"As I said, there was a fight between the two. Judging from the traces of the wound, I tend to think that her head hit the table, but it was not fatal. What really caused her to die was suffocation. It was not suffocation in the water, but was strangled by someone's throat. Her neck had bruises, but it was not obvious after soaking in water. It was not easy for ordinary people to find out. As for the fact that they knew each other, it was normal. At that time, it was already dark. If it were a man and a woman I didn't know, it was almost impossible to live in the same room."

"Where is that height? You said he is about six feet tall, so how did you infer it?" Zhang Heng asked.

"Well, this requires some skill," said Holmes. "I simulated their...Well, the position, the woman is lower and the man is upper. Then, compared with the bruises on the neck, you can determine the direction and angle of the palm, and then calculate the approximate height of the assailant is about the same as mine."

Sherlock Holmes talked freely and finally sorted out all the previous inferences before serving.

This is how many things in this world are. At the beginning, I felt very magical and incredible when I heard the conclusion, but once I knew the inference process, it seemed that it was not so mysterious, just like a magician's magic.

"Positive reasoning is easy. For example, you know that it is breakfast when you see bread, but otherwise it is not. This is also the ability that detectives need to exercise. If you want to learn, you can start by guessing a profession. From a person's sleeves, shoes, cocoon skin of his index finger, fingernails, shirts, expressions, etc., guess what profession he is engaged in. For example, the gentleman at the table behind you, just by observing, I can tell that he has just returned from Afghanistan and is a military doctor."

Zhang Heng showed a strange look on his face for the first time tonight when he heard this, thinking that it wouldn't be such a coincidence.
Chapter completed!