I Play Dungeons in the Police Station-Chapter 122 - 110: New Instance: Corpse Spokesperson
"Then you start."
As for being a forensic expert, Li Xiang really didn’t know a thing. In the scenario, he wasn’t afraid of losing face. Among the two people present, Zhang Yongliang, with his half-baked knowledge, was obviously better than him, but not by much.
"..." Zhang Yongliang felt a lot of pressure. The one who knew how to do it insisted on pretending to be clueless, and right now, he had no idea what to do.
"Stop messing around. If we screw up this case, the master will have our hides when he comes back."
"That’s why you need to try harder."
Li Xiang wasn’t afraid of that master he had never met. At worst, he could just walk away when the time came.
"Uh, let’s first confirm the time of death."
"How do we confirm it?"
"After death exceeds three days, ordinary pathology finds it difficult to accurately estimate the time of death."
"Then what should we do?"
"I’ve heard from the master that there’s a branch of forensic entomology in Forensic Medicine. This estimates the time of death based on the stages of insect growth and development on the corpse. Using blowfly maggots to infer the time of death can reach ten days, half a month, or even several months. Can’t we determine the time of death based on the maggots growing on the deceased?" Although Zhang Yongliang was an assistant, he had acquired some forensic knowledge by osmosis in the forensic department.
"Then let’s start."
"You really don’t know?" Zhang Yongliang looked at Li Xiang with suspicion.
"Just start. When the master returns, you won’t have a chance to show off."
Li Xiang gave the eager youngster some encouragement, making him even more convinced that Li Xiang was giving him a chance to perform. He got so excited that he became incoherent: "Okay... okay, I’ll go get the book now."
He had only heard of forensic entomology. Once, when tidying the master’s bookshelf, he had seen this book. Now, he thought of it and immediately went to fetch it, as combining theory with practice was the quickest way to learn.
In a short while, Zhang Yongliang came over with the professional book.
"I’ve found it. Flies go through four stages of development. At normal temperatures, the egg stage usually lasts 1-2 days. Fly larvae, commonly known as maggots, can be further divided into three instar stages, lasting about 6-10 days in total. The pupal stage usually lasts from one week to over ten days. Finally, the pupae metamorphose into adults."
"Different species of flies have different rates of development. Besides, factors that influence the type and development speed of maggots on a corpse include temperature, humidity, light, and the condition of the body."
Zhang Yongliang turned the book to the common Calliphoridae family, which are frequently used species to infer the time of death.
The maggots on this corpse were of this species.
Following the book’s instructions, Li Xiang and Zhang Yongliang collected the insects from the corpse. Some were killed with boiling water and preserved in ethanol for future analysis, while others were sent to a cultivation room to be reared at the crime scene’s simulated temperature to further confirm their developmental stage.
Early and mid-stage corpses are mainly infested by flies, while beetles are more prevalent during the middle and later stages. If empty puparia of flies, or beetles such as Silphidae and Dermestidae are found on the body, it indicates the corpse has aged.
Fortunately, the maggots on this corpse were from early and mid-stage red-headed blowflies.
Corpse decomposition consists of several stages:
Fresh stage: typically lasts 1-3 days, extending with lower temperatures, with no significant visible changes. Flies appear and lay eggs during this period; flies can deposit eggs on outdoor summer corpses within hours.
Bloating stage: lasts several days to several tens of days, characterized by body swelling, a strong putrefactive odor, and fly eggs hatching into larvae. It continues to attract numerous adult flies, ants, and beetles to gather on the corpse.
Decay stage: lasts several days to several tens of days, marked by advanced decomposition, tissue liquefaction, and a strong odor. Large numbers of maggots feed and create many cavities, exposing the skeleton. Maggots pile up and roll around, occupying most of the corpse, and fewer adult flies come to lay eggs. Pupae and post-emergence puparia may appear.
The female corpse was currently in the decay stage.
Finally, the dry stage: only hair and bones remain, most insects depart, leaving just a few ants and beetles.
Li Xiang and Zhang Yongliang worked on the body while consulting the book, somehow entering a learning mode, subconsciously ignoring the corpse’s stench. The scene was somewhat artistic.
It was hard to look directly.
"If it’s known that in field conditions, red-headed blowfly larvae take 20 days to develop into adults, and the maggots we collected emerged as adults after 10 days, we then know the maggots’ age is 10 days. Coupled with egg stage data, we can infer when oviposition occurred, hence the potential time of death."
The two painstakingly followed the book step-by-step, operating with extreme precision and care.
"Not bad. If it’s winter, simply inferring the oviposition time isn’t enough; we also need to know the interval from death to when the flies encountered the body. But in the outdoor summer, flies can quickly detect the scent of death, reaching the body in less than an hour, negligible really."
From the way they meticulously worked, you couldn’t tell that one was a clueless assistant and the other an almost-encyclopedic intern.
Anyone unaware might genuinely think they were forensic professionals.
After completing insect sampling, Li Xiang and Zhang Yongliang began cleaning the corpse’s insects, preparing to check the body’s height, age, and cause of death.
Height was easy to measure with a simple measurement.
Determining age, although complex, could be approached with numerous methods, easily handled by two dedicated academic achievers in the anatomical room.
At this moment, they planned to use the pubic symphysis to determine the deceased’s age.
First, a segment of the pubic bone was taken from the deceased.
They needed to accurately recognize the morphological features on it and, using appropriate formulas, calculate the age of the deceased. This method provided results with high precision, with an error margin of only two years.
Of course, they found this method in a book too, and they carefully compared the atlas in the book.
The morphological reference points on the pubic symphysis amounted to nine: the symphyseal groove ridge, ossification nodule, lower end of the symphyseal surface, ventral bevel, dorsal border, ventral border, oblique plane origin, symphyseal facial morphology, and symphyseal bone quality.
These features closely correlated with age changes.
Li Xiang and Zhang Yongliang compared the rating tables in the book as they evaluated the morphological features of the pubic symphysis, incorporating the corresponding scores into the formula for calculation: Y=M+X1+X2+...X9.
Y=estimated age, M: constant (male M=16.45, female M=15.32), X: score for each reference point.
Finally, with some difficulty, they calculated Y=32.6.
Next, it came down to determining the cause of death... and they were completely at a loss.
Li Xiang and Zhang Yongliang stared at the pitted skin, the nearly rotted corpse. Their meager knowledge reserve couldn’t possibly uncover her cause of death.
Two weeks later, Li Xiang and Zhang Yongliang submitted an autopsy report they believed was their best effort.
The deceased was a female, about 160 cm in height, approximately 32 years old, with a death time of 14 days. Cause of death: unknown. Only an intrauterine device was found in the body.
Subsequently, Li Xiang submitted the mainline task in the system.
[Ding, mainline task completion 75%, first-time task completion reward skill: Forensic Medicine, task rating: Grade C, reward skill experience +1000]
Immediately, a massive stream of information flowed into Li Xiang’s brain, covering basic medicine, clinical medicine, relevant criminal science technology, and forensic identification technology. The breadth of knowledge far surpassed previous scenarios.
Although only introductory, if Li Xiang were to learn it himself, it would take no less than three to five years.
It took Li Xiang quite a while to relieve the cognitive overload brought by this enlightenment. At this moment, he closed his eyes, gradually organizing the knowledge appearing in his mind, verifying it against the decaying body in the scenario.
If he could do it again, he’d surely do better this time.
