The first few pages of the forensic report sent by Gao An had nothing new. For example, the skin tissue of the deceased was found in the rope, and the rope used to hang the deceased had some wear and tear. These could only prove that the deceased had struggled.

No other people's DNA information was found in the rope, and no fingerprints or other things were found, which provided no more clues and did not help solve the case.

But the forensic report on the bathroom floor drain attracted He Jiahui's attention.

After DNA testing, in addition to the hair of the deceased, the hair of three other people was found in the bathroom floor drain.

But the place where the crime occurred is a B&B after all. There will always be different guests staying, and different guests will also be received in the bathroom. It is normal for the hair of several people to appear.

What He Jiahui noticed was not the DNA information, but another piece of information: a trace amount of sodium chloride was detected in the bathroom floor drain.

"Sodium chloride? How could this thing appear in the bathroom floor drain?" He Jiahui frowned and thought for a moment, and a bold idea came to his mind.

The next second, he said: "I may have guessed the murderer's method of committing the crime."

Du Xiaohe and Taishan all looked at He Jiahui, but He Jiahui did not explain. He walked to the sink, turned on the faucet, then took a handful of water with his hand, put it in his mouth and tasted it.

"It doesn't taste salty, it's just fresh water." He Jiahui said to himself.

The tap water in Xiangjiang is drinkable directly, so the people in Xiangjiang also call the tap water ‘drinking water’.

The fresh water on Cheung Chau Island is provided by the Silver Mine Bay Water Treatment Works on Lantau Island. Initially, there was only one 500 mm water supply pipe to transport fresh water from the seabed to Cheung Chau Island. Later, two more were added.

Du Xiaohe took out the thermos cup from his waist, handed it to He Jiahui, and said at the same time: "Jiahui, are you thirsty? I have boiled water here, you don't need to drink water."

"I'm not thirsty, I just want to check whether the water in the water pipe is fresh water." He Jiahui replied.

"Of course it's fresh water! This is daily water, you can't use sea water!" Du Xiaohe replied.

"Yes, no one knows how to wash with sea water." He Jiahui said, picked up the phone and dialed the phone number of Forensic Gao'an.

After a while, the call was connected, and Gao An's voice rang from the phone: "Sir He, I have sent you the preliminary forensic report. Have you received it?"

"I received it, read it, and found new clues." He Jiahui said.

"What new clues?" Gao An asked directly.

"I saw in your report that sodium chloride was detected in the floor drain." He Jiahui paused and then said: "Sir Gao, the clothes and shoes of the deceased should be at your place! I would like to ask you to test them.

, is there any sodium chloride in the soles of the deceased’s shoes?”

"Sodium chloride? Okay, I'll do the test now and get back to you as soon as possible." Gao An said.

Detecting sodium chloride is very simple. You can detect a single solution by licking it with your tongue. This is even more childish for professional forensic personnel.

He Jiahui did not wait too long when Gao An called back: "Sir He, I have tested it and the soles of the deceased's shoes are indeed stained with trace amounts of sodium chloride."

"As expected!" He Jiahui sighed softly and continued, "Sir Gao, I have to trouble you to come to Cheung Chau Island again. You also need to test the bathroom floor at the crime scene."

…

Gao An brought the detection equipment to the crime scene again.

"How is it? Is there any sodium chloride detected on the bathroom floor?" He Jiahui asked.

Gao An nodded: "A trace amount of sodium chloride was indeed detected."

"It seems that my guess is correct." He Jiahui sighed with relief and said to Du Xiaohe next to him: "I have good news and bad news now. Which one do you want to hear first?"

"What's the good news?" Du Xiaohe asked.

"The good news is that I have mastered the murderer's method of committing the crime." He Jiahui said.

"What about the bad news?" Du Xiaohe asked next.

"The bad news is that all our previous investigation ideas will be overturned. Most of the information we had before is useless. This case will have to be investigated from the beginning." He Jiahui replied.

Everyone present was confused, and Forensic Examiner Gao An even said: "Sir He, please stop trying to tantalize me. Just tell us what you are thinking of!"

He Jiahui said: "Sir Gao, don't you think it is strange that sodium chloride was detected in the bathroom?"

"Of course it's strange. The water used in the bathroom should be fresh water. Even slight sodium chloride should not appear here." Gao An replied.

"I will take you to a place and you will understand." He Jiahui replied.

…

He Jiahui led everyone to the fishing port pier.

The residents on the outlying islands originally made a living by fishing, so there are naturally piers here that gather fishing boats. Summer is the season when typhoons are most common, and fishing at sea is more dangerous, so many fishermen do not choose to go to sea, but rest at home.

He Jiahui took the suspect's photo and asked door to door, and finally got a clue from a fisherman.

"Uncle Wen, are you sure this is the person?" He Jiahui asked, pointing to the photo.

The fisherman named Uncle Wen looked at the photo carefully again, and then said: "It's him, you can't admit it. The fishing boat pier is fishy and smelly. Most tourists will not come here. Strangers come.

And he also bought something from me, I will definitely remember it in my mind."

"Thank you, Uncle Wen!" He Jiahui thanked him, then turned and walked out.

Gao An next to him looked at He Jiahui with admiration.

"Sir He, I am really convinced by you. The murderer actually used such weird means to kill people. Anyone else would never have guessed it," Gao An said.

"I also saw the mention of sodium chloride in your forensic report, and that's when I thought of this possibility. If you hadn't been careful in forensics, it would have been difficult to solve the case." He Jiahui also gave Gao An a business blow.

.

At this time, Du Xiaohe and others also stepped forward and asked: "Sir, have you confirmed who it is?"

"Confirmed, he is the murderer!" He Jiahui handed a photo to Du Xiaohe.

Du Xiaohe lowered his head and saw that the person in the photo was his assistant Chen Weiting!

…

"Mr. Chen Weiting, you are suspected of killing Ms. Zheng Jiazhen. You are going to be arrested now. You can remain silent, but everything you say will become evidence in court!" He Jiahui said with a serious face.

Seeing that the police wanted to arrest him, Chen Weiting reacted very strongly. He screamed loudly: "You have wronged me. I did not kill anyone. I have an alibi! I was not here at all on the night that Zheng Jiazhen died. The immigration department can prove it."

I went to Macau, there is no way I could kill anyone!"

He Jiahui said: "Mr. Chen, you were not at the scene when Zheng Jiazhen died, and you have an alibi, but this does not mean that you are not the murderer!

I have to say that you are very smart. You used a method of delaying the killing and successfully misled the direction of our investigation. You also took the opportunity to create an alibi and clear yourself of suspicion."

"What are you talking about delaying the killing? I don't understand what you are talking about!" Chen Weiting defended.

Seeing that Chen Weiting was still being stubborn, He Jiahui had no choice but to expose Chen Weiting's murderous methods.

"There is no doubt that this case was committed by an acquaintance, so the murderer must be someone from your crew. This is certain, and our investigation has always been directed in this direction.

Forensic medical examination results show that the time of death of the deceased was between 2 a.m. and 4 a.m., so we take it for granted that the murderer committed the crime between 2 a.m. and 4 a.m.

However, the result of our investigation was that between two o'clock in the morning and four o'clock in the morning, everyone in your crew had alibi. At that time, I became confused about this time. Later, we returned to the scene of the crime and conducted

I replayed the case and found a lot of doubts."

He Jiahui paused deliberately, then slowed down his speech and continued;

"First of all, the deceased was very neatly dressed. It is obviously unreasonable for a person to stay in his own residence at two o'clock in the morning, fully dressed, and even put on heavy makeup. Even if this person is a night owl and does not intend to sleep,

Take off your makeup and put on some comfortable pajamas, right?

So I thought, could it be that the deceased had been subdued by the deceased without even having a chance to remove makeup and change clothes. In this case, the starting time of the crime was probably not between 2 am and 4 am.

.

I thought at the time that the murderer subdued the deceased very early, and then waited until between two and four o'clock in the morning to kill the deceased. I even suspected that the murderer was asking the deceased some questions, so he did not kill her immediately.

The second doubt is that the deceased has obviously been tied up by the murderer and has completely lost the ability to resist. Why did the murderer not directly strangle the deceased, but instead go to trouble to hang the deceased? Isn't this a more complicated killing method?

.

This is something I still couldn't figure out until I saw the report from the Forensic Department. They found sodium chloride, which is salt, in the floor drain of the bathroom at the crime scene.

So I asked forensics to do another test, and found that salt was also detected not only in the floor drain, but also in the soles of the deceased's shoes and on the bathroom floor.

The bathroom is a place for bathing, and the water must be clean. How can there be salt on the ground? Even if the deceased had played in the sea and was stained with salt water, the salt should have been washed away after washing in the bathroom.

It was also at this time that I guessed the murderer's modus operandi. The murderer used ice cubes to create a mechanism to delay the murder, and at the same time created an alibi for himself."

As He Jiahui spoke, he stared at Chen Weiting closely, but Chen Weiting still looked calm, as if what He Jiahui was talking about was not him. His psychological quality was obviously much better than that of other people in the crew.

Chen Weiting would not shed tears until he saw the coffin, so He Jiahui could only let him die. So He Jiahui continued to explain:

"Let's start from the afternoon of the day when the crime occurred. After you finished shooting, you returned to the B&B. Then you came to the deceased's room, and when the deceased was not prepared, you used drugs to knock her out.

It was also because you committed the crime in the afternoon, not late at night, and it was not yet time to rest, so the deceased was fully dressed and had not even had time to take off his makeup.

Then you tied up the deceased's hands and feet and blocked the deceased's mouth with tape so that she could not call for help or escape. Then you went to the bathroom and prepared the rope.

You brought another large ice cube and placed it in the bathroom. Then you hung the deceased on the rope in the bathroom and let her step on the ice cube.

Of course, you have calculated the length of the rope so that the deceased's feet can just step on the ice without escaping. In this way, if the deceased wants to live, she can only step on the ice. Once her feet leave the ice,

will be hanged.

But the ice cubes will melt slowly. As the ice cubes melt, the deceased's feet will slowly lose their support. When the ice cubes melt to a certain extent, the deceased's feet can no longer touch the ice cubes.

She will be hanged.

This was a slow process, lasting several hours. I think the deceased had woken up during this process. She struggled and cried during this period, but to no avail. In the end, she could only watch helplessly at her feet.
To be continued...