Criminal Investigation Notes

Chapter 33:

Chapter 33:

As he spoke, all the people present looked puzzled, wondering where Su Hui had deduced his conclusion from. Even the forensic expert Jiang Xiang curiously approached and everyone gathered around Su Hui, who was kneeling on the ground, waiting to hear his explanation.

Lu Junchi had introduced Su Hui as a new consultant to the Major Crimes Unit and on their way there, they exchanged polite greetings. However, he could still sense that Captain Qi had some doubts about Su Hui. Perhaps he thought that Su Hui looked too young and frail to have any experience.

Now, Su Hui had only been at the scene for a short while when he suddenly spoke out with his doubts about the witness testimony. Captain Qi was getting annoyed.

"If we go by the testimonies of those few witnesses, the suspect broke the lock and went straight to Xie Peilan who was in the living room, wielding a weapon. Before his wife could react or scream, he quickly knocked her down. The killer used a weapon resembling a baseball bat and repeatedly struck Xie Pailan's head, causing her death. At this point, the mother-in-law heard the sound and came down." Su Hui said, looking up at Captain Qi. "I repeated it correctly, right?"

Captain Qi nodded, "Yes, that's what they all said. What's the problem?"

Su Hui turned his head and pointed to the bloodstains on the wall. "But this bloodstain shows a completely different scenario from the testimony."

The forensic expert Jiang Xiang was puzzled, "This is a blood spatter, caused by gravity strikes. By the time we arrived, it had already dried up and we conducted an extraction and analysis." He compared the analysis results, "The blood belongs to Xie Pailan, we didn't find any alcohol or drugs, and there was nothing else special..."

Su Hui explained as he pointed to the bloodstain, "The special thing is not in the blood, nor in the spatter pattern. With each strike, Xie Pailan's blood would spatter on the wallpaper, forming bloodstains. When the strikes stopped, the blood would have time to seep into the wallpaper. When the bloodstain was semi-dry, new bloodstains would spatter again. At this point, the excess blood would flow down the wall, but some of the blood would still continue to seep in."

His fingertips glided over the red surface, pointing to the lighter areas and then to the darker ones nearby. "It's because of the repeated splashes and seepage that we can see the varying shades of these bloodstains."

Lu Junchi understood what was being said and crouched down to observe closely. "So the darker areas may have been sprayed with blood multiple times, while the lighter areas may have only been splattered once?"

Su Hui nodded in agreement. "The areas where blood has seeped more will have a slightly darker color." He pointed to the deepest part in the middle. "There may have been three sprays of blood here."

"That makes sense..."

As soon as Su Hui pointed out these anomalies, Jiang Xiang noticed them too. These were tiny details that he and the previous examiner had overlooked. "The differences in color depth are caused by the seepage of blood. If fresh blood sprays on the wallpaper before the previous blood has had time to seep in, the two will mix together and not leave these marks."

Su Hui continued to point to the wallpaper. "I've looked at this wallpaper, and its permeability isn't very strong. It can only form these kinds of marks if there was a relatively long interval between the strikes."

Jiang Xiang nodded repeatedly on the side, "Advisor Su, your analysis makes sense. Later on, we will collect some wallpaper and conduct simulated experiments in the material identification laboratory to see how long it takes to form such marks."

Lu Junchi stood up to summarize, "Anyway, this shows that Xie Peilan did not die immediately. The testimony is indeed problematic."

Su Hui pointed to the side again, "And here." Everyone followed his slender finger to see two marks, both located relatively low. One was a vertical bloodstain with some friction marks, and the other was a faint circular bloodstain.

Su Hui said, "The bloodstain with friction marks is likely caused by the victim's head sliding against the wall when she fell, and the other one next to it may be caused by the victim touching the wall with her hand. The victim should have struggled and called for help."

Listening to Su Hui's analysis, Captain Qi's face turned red with embarrassment, but he had to admit that these were pieces of evidence they had overlooked before. These marks all indicated that the victim's death process was prolonged, which did not match the testimony.

The killer struck Xie Peilan's head hard, then after a while, struck a few more times. This process may have been repeated several times.

This poor woman once lay on the floor, moaning, convulsing, struggling, until she died...

How could her family not have noticed the long and cruel process of the attack?

Jiang Xiang wrote down these points and took photos, saying, "Thanks to Consultant Su, I will supplement the report later..."

Captain Qi admitted his previous mistakes when he heard this, gritting his teeth and saying, "It's still Consultant Su who observed carefully... There are indeed many doubts in this case. We may need to question those people related to the case again."

Su Hui lowered his head and said, "We still need to conduct experiments before we can draw conclusions."

Hearing their praise for Su Hui, Lu Junchi was even happier than being praised himself. He stood up and thought about how to continue the investigation.

The case soon found a breakthrough point, and the inconsistencies in the testimony indicated that there were hidden facts in this case.

He flipped through the previous visit records. If it was really as Su Hui had deduced, then the neighbors couldn't have not heard anything.

After Jiang Xiang and Captain Qi left, Lu Junchi was about to call someone to go downstairs and chat with the neighbors again, when he suddenly heard Su Hui whisper his name.

Lu Junchi bent down and asked, "What's wrong? Do you have any other questions?" Then he realized something was off and frowned, "Why are you still kneeling?"

Su Hui sighed and didn't say anything, but gestured to him with a finger.

Lu Junchi helplessly leaned closer to him.

Su Hui then leaned over and whispered in his ear, "My legs are numb and I can't stand up. Can you help me?"

Lu Junchi: "..."

Su Hui was kneeling in front of the TV cabinet, obviously unable to stand. Lu Junchi bent down in front of him and lifted him up from under his armpits, helping him stand.

Su Hui was very light and didn't seem to weigh as much as he should for his height. His legs were completely numb, and he couldn't use any force on his waist. He leaned on Lu Junchi's body, holding onto his clothes and gasping.

Lu Junchi asked, "Is it very numb?"

Su Hui replied, "I can't move yet. Can you let me lean on you for a while?"

Lu Junchi hesitated for a moment, then reached out and hugged Su Hui's waist. He was so thin...

The two of them were very close together, and from behind, it looked like Lu Junchi was holding Su Hui.

Jiang Xiang's eyes glanced over in their direction, but quickly turned away, saying, "I have something to ask Captain Qi..."

Lu Junchi didn't pay any attention at all, but then he saw that Su Hui's shoelaces were untied, and sighed, "You..."

In his view, Su Hui was really troublesome enough. As such an intelligent person, why couldn't he take care of himself?

When Su Hui stood still, Lu Junchi squatted down and skillfully tied a bow for Su Hui's shoes.

Su Hui narrowed his eyes, revealing his under-eye bags, "Thank you, Captain Lu."

Lu Junchi said, "Why don't you find a place to sit for a while? I'll go check on the neighbor."

Su Hui rubbed his legs that had just recovered, took a few steps, and sat on the stairs of the duplex building.

He was afraid that his previous back injury would recur, so he didn't dare to bend over, keeping his back straight. His sitting posture looked like that of a child sitting at the stairs waiting for his parents to come home.

Lu Junchi called a young police officer and was about to go downstairs, but after a moment's thought, he returned and handed Su Hui's backpack and the case files to him.

Su Hui thanked him and sat on the stairs of the duplex building, flipping through the photos of the corpses.

In the photo, Xie Pailan's eyes were half open, and the right side of her head to her ear was a bloody mess. Blood and brain tissue had long been entangled with her hair, and her death was incredibly tragic.

If this case was not the work of those unknown robbers, then who was the real culprit?

Su Hui stared at the photos and could sense the intense hatred the killer had toward Xie Peilan...

The image of the killer gradually took shape in his mind, and the entire process of the crime became clearer and clearer.

But those were just theories, he still needed actual evidence to prove his deductions.

Su Hui suddenly lifted his head and asked Jiang Xiang, "Jiang *Wujian, did you bring luminol with you?"

(wu jian) Lit: Material Examiner - I think this might refer to a crime scene investigator. So, I'll use 'Investigator' from now on. Or should it be 'Analyst'? This is based on my deduction of the role he's playing. Seeing as he's at the crime scene and not a lab Crime Scene Investigator/Forensic Analyst is the job description that matches him the most. But if there is someone who can give me a more accurate translation for this, then comment down below.

"I did," Jiang Xiang replied, holding two bottles of luminol that he had been carrying with his forensic kit all along. "Where do you think there might be blood stains?"

"I'm just guessing..." Su Hui said. "Can you help me spray the wall behind the sofa?"

Jiang Xiang put on a mask, took two steps forward, and looked suspiciously at the wallpaper behind the sofa. Although there were some faint traces there, it couldn't be confirmed that they were blood stains.

He sprayed some luminol on the wall, and after a while, Jiang Xiang exclaimed at the fluorescent color that appeared.

The room was filled with the familiar sour smell of luminol, and Su Hui coughed for a while before stabilizing. He couldn't see clearly and had to ask, "Did you find anything?"

Jiang Xiang looked at the spots gradually appearing on the wall and replied, "Yes."

Luminol reagent is a mixture of luminol and hydrogen peroxide, it is highly sensitive and able to detect blood with content as low as 0.01%. It is particularly suitable for detecting trace or old blood stains that have been wiped away.

Su Hui felt relieved and said in a hoarse voice, "Okay, then spray other places too."

"Where?" Jiang Xiang asked.

"Anywhere, blank spaces, walls, and floors," Su Hui said.

Jiang Xiang took the reagent bottle and started spraying, revealing more traces on the walls and floors.

Su Hui then said, "Close the curtains and take a look."

Jiang Xiang sighed and closed the curtains. The environment darkened, and like magic, many fluorescent traces of blood appeared on the off-white wallpaper and the gaps on the floor. These traces were obviously wiped away blood stains.

Even if Su Hui had poor eyesight, he could see that the walls of the room were suddenly covered in blood stains. For a moment, the entire first floor looked like a haunted house.

TN:Luminol 

Luminol (C8H7N3O2) is a chemical that exhibits chemiluminescence(Chemiluminescence is the emission of light (luminescence) as the result of a chemical reaction.), with a blue glow, when mixed with an appropriate oxidizing agent. Luminol is a white-to-pale-yellow crystalline solid that is soluble in most polar organic solvents, but insoluble in water.

Forensic investigators use luminol to detect trace amounts of blood at crime scenes, as it reacts with the iron in hemoglobin. Crime scene investigators use luminol to find traces of blood, even if someone has cleaned or removed it. The investigator sprays a solution of luminol and the oxidant. The iron in blood catalyzes the luminescence. The amount of catalyst necessary to cause the reaction is very small relative to the amount of luminol, allowing the detection of even trace amounts of blood. The blue glow lasts for about 30 seconds per application. Detecting the glow requires a fairly dark room. Any glow detected may be documented by a long-exposure photograph.

Also, time to name-drop another recommendation. CSI which stands for Crime Scene Investigation is a show that follows an elite team of forensic experts as they use high-quality crime scene investigation techniques to crack cases and find evidence to catch criminals. There are a bunch of them namely CSI: Crime Scene Investigation, CSI: Miami, CSI: Vegas, and CSI: NY. My personal favorite is the OG, CSI: Criminal Investigations followed by CSI: Vegas. You can watch any one of them since they have no intersection. It's not on Netflix sadly... I pirated them. *ssh* I had no choice don't judge me! 

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