The Genius Female Forensic Pathologist, The Psychological Anatomist

"Has your daughter exhibited any unusual behavior recently?"

"Not really. She goes to work and comes home as usual every day. However, Xiaoning recently got a boyfriend and often goes out on dates with him, coming back very late at night, sometimes not coming back at all," Sun's Mother said. "We thought she's an adult now, so we didn't interfere much with her social life."

"When did she start dating this boyfriend?" Fang Rui asked.

"About two months ago."

"Boyfriend? Did she say her boyfriend is a boy?" Zhang asked again to confirm.

Wang Yonghua is already in his forties, so it's unlikely he would be described as a boy. Could it be that the boyfriend Sun Xiaoning mentioned is someone else?

"Yes, that's what she said," Sun's Mother replied, then added, "Xiaoning has been acting a bit strange lately. She suddenly became very rich, bought a lot of luxury items, and even a car. When I asked her where the money came from, she said it was from stock trading and that we would soon live a good life. Could she have done something illegal? How could a girl suddenly earn so much money?"

"We are still investigating," Fang Rui replied.

Zhang asked, "Do you know about your daughter's relationship with Wang Yonghua?"

Sun Xiaoning's parents looked puzzled. "Who is Wang Yonghua? We've never heard of him."

"Didn't your daughter mention him?"

"No."

"Have you seen your daughter's boyfriend?"

Sun's Father said, "No! My daughter never showed us a photo. She seems very fond of him, but when we asked about the boy's background, she wouldn't tell us."

Sun's Mother covered her face and burst into tears. "It's all my fault. How could a girl suddenly have so much money? She must have gotten it through improper means. Waaah, when she was coming home late, why didn't I talk to her more and understand her situation better?"

Sun's Father also started blaming himself and crying.

Zhang quickly handed them tissues.

In the autopsy room.

The female victim, apart from ligature marks on her neck and a few scratches on her back, had no other external injuries and no signs of resistance.

"At the time of the incident, the victim probably got into the car to look for something, and the assailant strangled her from behind, killing her quickly," Chen Xue analyzed. "The scratches on the victim's back were likely caused during sexual intercourse with the male victim, which explains why there were skin cells under the male victim's fingernails."

Mu Mian and her team had already extracted all the skin cells from the victim's fingernails. Mu Mian noticed that the victim's nails seemed to contain two types of skin cells: one fair and delicate, the other rougher.

The male victim's injuries were more complex. He had bruises from resistance, multiple contusions on his head, and a fractured skull on his forehead.

Mu Mian cut open the male victim's scalp and found that his frontal, left parietal, and left temporal bones were all depressed, with severe intracranial damage.

Mu Mian and Chen Xue carefully observed the morphology of the depressed fractures, finding five depressed areas, which were narrow and had a certain curvature.

Mu Mian had seen similar wound patterns in most of the domestic autopsy reports she had read, and the weapon used was a large wrench.

"The weapon could be a large wrench," Mu Mian said.

"Yes, if the wrench is held sideways and struck, it could cause such wounds," Chen Xue agreed.

Mu Mian then wiped the blood off the skull to further observe the wounds. She noticed some black substances in the depressed areas.

She used a cotton swab to wipe it and examined it closely.

"This should be engine oil! When I was a kid and my bike's chain fell off, I would get engine oil all over my hands while fixing it," Chen Xue analyzed. "How did the wrench get engine oil on it? Ah, this wrench was probably used for repairing cars! But ordinary people wouldn't keep a wrench in their car, and unless they were fixing the engine, it wouldn't get engine oil on it. Unless the assailant brought it themselves."

Chen Xue noticed Mu Mian silently watching her and began to doubt herself. "Mian, did I get it wrong?"

"Chen Xue, I realize I lack some common sense. I don't know about those things. I don't have a bike, I've never had a chain fall off, and I don't have a car," Mu Mian sighed.

It seems she should watch more TV dramas. Fang Rui's mother recommended many family dramas to her the other day, saying they could broaden her perspective on solving cases. Mu Mian initially didn't want to watch them, but she felt she needed to learn some common sense.

"Mian, that's why a team is necessary. We complement each other!"

At the morning meeting the next day, Mu Mian reported the autopsy results.

"The time of death for both victims was between 10:00 PM and 10:30 PM on June 23rd, the night before last."

"The cause of death for the female victim, Sun Xiaoning, was strangulation. We detected semen on her body, which belongs to Wang Yonghua. She had three scratches on her back, caused by Wang Yonghua, as part of the skin cells we found under Wang Yonghua's fingernails belonged to Sun Xiaoning."

Mu Mian continued, "The cause of death for the male victim was craniocerebral injury, resulting in subarachnoid hemorrhage. The weapon used to kill him was a wrench, and it should have had engine oil on it."

Fang Rui asked, "Whose skin cells are the other part under Wang Yonghua's fingernails from?"

"That's a good question," Mu Mian said excitedly. "The skin cells under the victim's nails belong to two people, and the other person should be male."

"Could it be that the victim scratched the assailant during the struggle?" Zhang analyzed.

Mu Mian rebutted, "If that were the case, why wouldn't the assailant clean up that evidence? Or just cut off the victim's fingers and take them away, so there would be no evidence left at all."

This assailant was too careless, making such a basic mistake.

Chen Xue said, "Could it be that he acted on impulse and didn't think that far? Passion killings usually leave a lot of evidence."

Zhang had a bolder guess and said, "Who benefits the most from Wang Yonghua's death? Definitely his wife! Could it be that his wife hired a hitman? I feel like his wife isn't at all sad or surprised about his death, as if she knew it would happen. If it was a professional killer, he wouldn't be afraid of leaving DNA evidence, as he would just flee after completing the job."

"If his wife hired a killer, wouldn't she want to torture Sun Xiaoning severely? Usually, women hate the other woman the most, but the assailant only strangled Wang Xiaoning," Chen Xue analyzed. "It seems the assailant hated Wang Yonghua more."

"But Wang Yonghua's wife seems to have a good relationship with Wang Yonghua's other lovers; she even has their contact information. She doesn't seem to care about Wang Yonghua's other women."