Diary of a Criminal Investigator

Dissection Room.

The Forensic Doctor held the nail extracted from Zhao Kai’s body and sighed.

All four bodies were dissected by these two forensic doctors, each had a nail driven into its head.

"Do you think the perpetrator is quite superstitious?"

Chen Jiang observed the nail for a long time and confirmed that the nail in Zhao Kai’s head was the same size as those in the first three bodies.

Just ordinary iron nails.

"Who knows what’s going on, but there’s a rumor around here that such nails can suppress a dead person’s soul, though it’s just superstition."

"This matter should be studied by Captain Gao and his team."

Chen Jiang and the two forensic doctors from Binzhou City’s Criminal Investigation Team guessed right; Gao Xiang was indeed studying this case.

In the conference room, Li Donglin, Gao Xiang, Lu Chuan, and several other members of the major crimes unit were present.

It was already afternoon, and the provincial forensic analysis center had sent over the trace evidence analysis results.

"Lu Chuan, please report first."

Director Li Donglin always placed a high level of importance on the Crime Scene Investigation team here.

And Lu Chuan never let him down, playing a significant role in solving multiple cases.

One could say the major crimes unit maintained a 100% case-solving success rate, and Lu Chuan’s contributions were indispensable.

"Yes, Director Li!"

Lu Chuan’s eyes were bloodshot from exhaustion.

He arrived in Binzhou City yesterday morning and hadn’t rested at all, staying awake for twenty-seven or twenty-eight hours until this afternoon.

Despite being physically exhausted, Lu Chuan was in a heightened state of mind.

This morning, after receiving the foot impression molds sent over by Luo Qiang’s team, Lu Chuan conducted a detailed analysis and compared them with the half-bare footprint discovered at the crime scene’s washbasin area.

He obtained many valuable clues, roughly narrowing down the suspect’s physical characteristics.

In addition to analyzing the footprints this morning, Lu Chuan also asked Wang Hao and others from the Binzhou Criminal Investigation Team to take him to the previous three crime scenes.

After the second on-site investigation, he collected some more valuable clues.

Although he hasn’t completed a full technical appraisal yet, Lu Chuan already had some preliminary thoughts.

"First, let me report on the fingerprint identification analysis collected at the crime scene."

"The killer seems to have worn gloves throughout the act, being very cautious and leaving no fingerprints."

The Binzhou City’s Criminal Investigation Team had anticipated this.

No clear fingerprints were found at the first three crime scenes, so it would be impossible to leave such a flaw at the fourth.

"Second, we found some bloodstains in the washbasin area at the crime scene; the killer washed up there."

"We collected some trace evidence from the drain, and the provincial center did a technical appraisal overnight. Everyone, look at the test results."

The projector displayed multiple photos and a technical appraisal report.

"The bloodstains in the washbasin have been identified and belong to the victim, Zhao Kai."

"We also found skin flakes and hair strands, identifying three people’s DNA samples."

"One belongs to Zhao Kai, another to his wife, Li Guifen, and the third person..."

Lu Chuan maneuvered the projector to display a separate report.

"The system comparison did not find this person’s DNA sample information."

"I inquired, and according to our colleagues from Binzhou’s Criminal Investigation Team, Zhao Kai and Li Guifen lived alone, and it was rare for outsiders to be in their house."

Upon hearing this information, Li Donglin and the others were invigorated.

"Left by the killer?"

"Very likely!"

"It should be left by the killer. Zhao Kai and Li Guifen’s child has never visited this house after they got married."

"The third person’s DNA sample left there must be the killer’s."

Li Donglin intensely looked at Lu Chuan; even though the DNA sample isn’t matched in the system yet, this clue will eventually help pin down the suspect once the suspect range is determined!

"Any other clues?"

Lu Chuan nodded, "Yes, I also visited the previous three crime scenes today and conducted careful examinations of the washbasin and bathroom areas, collecting some sample evidence. They’re sent to the provincial forensic analysis center, and we should have results back by tomorrow night at the latest."

"If similar DNA sample information is found at the other three scenes, we can be certain that the owner of this DNA sample is the killer."

"Good!"

Although Li Donglin had high expectations for Lu Chuan, he didn’t expect such a substantial breakthrough from him.

However, Lu Chuan’s report wasn’t finished: "Besides that clue, I’ve also found a half-bare footprint on the floor near the washbasin at Zhao Kai’s murder site."

Half a footprint?

Lu Chuan adjusted the projector to display a pair of slippers.

"After the murder, the killer didn’t clean the floor, and all the shoeprints on the ground were slipper prints."

"This indicates two things: first, the killer and the victim likely knew each other, else he wouldn’t be wearing slippers inside the victim’s home."

"Second, during our on-site examination, we didn’t find bloodstains on any slippers, so I guess the killer cleaned the blood off them. Using reagent testing, we confirmed it, the slippers the killer wore."

On the projector was the pair of slippers, detected with blood traces, found at the entrance by Lu Chuan.

"He cleaned the slippers on the washbasin. The killer was quite cautious, likely cleaning one shoe at a time, avoiding leaving footprints on the ground."

"But while swapping the slippers, it was impossible to always have both feet on the slippers, so we found a half-bare footprint."

"Additionally, with the marks found by Luo Qiang’s team on the wall and a trail of footprints outside, I’ve conducted a comparison analysis."

"It can be confirmed that the footprints outside the wall are indeed left by the killer, who entered the complex by climbing over a wall."

"Judging by these footprints, the perpetrator is male, about 1.81m to 1.83m in height."

"Weighed between 75 to 80 kilograms, aged around 40, with a margin of error of no more than 2 years."

"Aside from that, the perpetrator’s arms are a bit longer than average."

Lu Chuan adjusted the projection, showing several photos of blood drops.

"This is the dripped blood I collected at the crime scene."

"Generally speaking, an average person’s arm length is about 2/5 of their height, but analyzing the dripped blood, the arm’s drooping height is approximately 85 centimeters."

"For someone around 1.8 meters tall, the arm’s drooping height should be around 80 centimeters, suggesting the perpetrator’s arms are longer than average."