Free Web NovelChapter 557: Chapter 527 Traceless Clues_1
Peng Shinian furrowed his brow, an expression that left Mr. Zhao feeling uncertain. Just when Mr. Zhao was about to press for more details, Peng Shinian took a deep breath and said earnestly,
"I’m not sure how to explain it, but the toxicity of this poison is similar to that of tetrodotoxin (TTX). It mainly inhibits nerve conduction by affecting sodium channels. In short, it’s an extremely terrifying toxin with a high fatality rate.
In nature, consuming shellfish that have eaten toxic blue-green algae after red tides can cause poisoning. Moreover, PSP persists in shellfish in a bound form, so the shellfish themselves are not harmed by ingesting the toxin;
When humans consume food containing the paralytic shellfish toxin, the toxin quickly releases and exhibits its toxic effects, with an incubation period of only a few minutes to a few hours. Symptoms include limb muscle paralysis, headache, nausea, drooling, fever, rashes, and the like.
In severe cases, muscle paralysis, breathing difficulties, and even asphyxiation leading to death may occur. This is just the concept of consuming it in small amounts. Poisoning via injection or through a wound would be both quicker and more severe. Of course, PSP can also be extracted artificially. I’ve read related papers on the subject. However, due to the instability of the toxin, strict storage conditions are required. It can’t be freeze-dried and can only be kept in liquid form."
Liu Yongxin became more and more shocked as he listened and raised his hand to stop Peng Shinian.
"Wait a minute, Peng, are you saying that one must use a large number of infected shellfish, or even find blue-green algae containing PSP, to purify it? And since the toxin in liquid form is inconvenient for transport and storage, it might be extracted locally?"
"Yes."
With the affirmative response, everyone stood up. freēwēbηovel.c૦m
"Does that mean that even if the murderer can’t create the poison themselves, they are someone who is very familiar with this toxin and can easily obtain it? To obtain these amounts of PSP, a corresponding laboratory would be needed. Peng, what conditions are required to extract this PSP, and how much raw material would be needed to produce a quantity sufficient to soak arrows?"
Peng Shinian pushed up his glasses with a deep frown.
"I don’t know; I need to calculate that. I need to look up related research data, and I also need information on all the laboratories in the Qindao Area. After all, the extraction of PSP isn’t a very high-end experiment, but it requires a substantial amount of raw materials. I’ll tell you the specifics after I’ve done the calculations."
Liu Yongxin nodded.
"Having a direction is better than none. So, start the calculations. Zhu Xingxing, visit Cui Lili later to inquire about the information on laboratories in the Qindao Area. I believe at least a level-one laboratory, registered with health or veterinary supervisory departments, would be capable of this.
Mr. Zhao, report to Director Xu. As Peng mentioned, extracting such a large quantity of the toxin will require substantial raw materials, which cannot be acquired from ordinary seafood markets. These places usually sell aquacultured or generally caught seafood. By the way, Peng, can PSP be extracted from all shellfish?"
Peng Shinian shook his head, lifting his cellphone and saying,
"I just did a search. Hua Country has conducted research on PSP. I found a document from 2010. According to the record, Hua Country has a distribution map of PSP in the sea. Around Nanyue Province, 13 categories of shellfish were discovered with toxicity levels ranging from 152 to 198 MU/(100 g)-1.
In the sea area near Bin City, 8 categories were found, with the highest level of shellfish toxins also below 200 MU/(100 g)-1. In the Qindao sea area, 3 categories were discovered with toxicity levels of 652 to 117 MU/(100 g)-1, among which the highest was the Yesso scallop."
"What’s a Yesso scallop?"
Mr. Zhao was bewildered, for all the terminology was leaving him confused at the moment. Peng Shinian quickly enlarged the image from the document to show to Mr. Zhao and the others.
Glancing at it, Mr. Zhao was astonished.
"Damn, isn’t that just a scallop? This thing is poisonous?"
Liu Yongxin slapped Mr. Zhao, the crisp sound silencing the office murmurs.
"Can’t you listen to the whole explanation? Didn’t Peng say it’s not the scallops themselves but because this type of shellfish is good at using blue-green algae, and PSP doesn’t affect them? They can accumulate it inside, like a sieve, existing within them. In specific sea areas, they come into contact with toxic blue-green algae frequently, which leads to the formation of toxic scallops, right?"
Peng Shinian shrunk bashfully, nodding vigorously.
"Mr. Liu is impressive, exactly right. However, that report only provides a regional map and doesn’t mark the specific locations in Qindao. I collected some information before I came here about scallop aquaculture areas, but I’m not sure if they are Yesso scallops."
Liu Yongxin waved his hand.
"Pang Tianhang and Zou Jialong will help you look up the data. If you need any local data, they’ll contact the leaders for you. Let’s start investigating separately now. Mr. Zhao Xinli, have you found anything else at the scene?"
Mr. Zhao snapped his fingers, bringing his notebook over to Liu Yongxin. He knew Liu Yongxin’s capabilities.
"There are also footprints, from the grass to the edge of the brick path, a total of four footprints, one of which is only a half print, very fresh. I’m not familiar with the shoe pattern, but the size is 44. As for the height and weight, I don’t know how well I’ve estimated, Mr. Liu, please take a look."
Liu Yongxin put on his reading glasses, carefully examined the photos and videos, slowed down the playback speed, and observed meticulously. Finally, holding the printed image of the footprint, he stood by the window and after a long pause, slowly began to speak:
"I’m not familiar with the pattern either, but did you notice something? These shoes are about 90% new, yet the wear on the outside of the left heel is more severe than on the right heel, and the right footprint is deeper."
Mr. Zhao nodded and moved closer to Liu Yongxin.
"I noticed that, people who play soccer regularly or engage in contact sports tend to have different pressures on their feet and may also have a shift in their center of gravity. Of course, external injuries, anterior pelvic tilt, and scoliosis could also result in such a gait, but with only four footprints, and none made while walking, it’s impossible for me to make an accurate judgment."
Liu Yongxin shook his head.
"Even though these were not made while walking, two of these footprints were left while he was crouching. According to Mr. Qu, there were no images found of him going in or out, and this person also didn’t know when Zhou Ning would return home, so he had to keep a long stakeout. Who could squat in one place and leave only four footprints?
Based on normal estimates, we leave work at 17:30, and the earliest Zhou Ning could get home was 17:45. Do you know what time the incident happened yesterday?"
"He arrived at the hospital at 23:47, Mr. He said he heard a loud bang, rushed downstairs, and saw Zhou Ning lying on the ground. He called out to Zhou Xiaoyu, didn’t delay, and immediately took Zhou Ning to the hospital, which took about ten minutes. So the incident happened around 23:37."
"Going by what you just said, if the incident happened at 23:37, then how long is that from 17:45 to 23:37? And it’s not like someone could just time it perfectly, which implies a stakeout of at least six hours. Could you crouch here without moving for that long?"
Mr. Zhao thought about it, mimed a crouching position, and then shook his head.
"With my weight, not only could I not crouch for six hours, but my legs would also go numb after just ten minutes. Even if one could manage not to eat or drink for six hours, could they really not go to the restroom? But Mr. Liu, do you think it’s possible he knew when Zhou Ning would be home and thus didn’t need such a long stakeout, with just temporary preparations needed?"
Liu Yongxin furrowed his brows tightly and quickly dismissed the thought.
"I’ve considered this before. The timing of your interrogation of Liu Tiesong with Director Xu yesterday was extremely uncertain. Not many people knew when you finished, just the group involved, along with some members of the forensics department and the criminal police team.
Oh right, there’s also Mr. Hu and Director Xu, but the likelihood of a leak is very low, unless someone, not knowing the details, could infer when Zhou Ning would return, but that would significantly reduce the accuracy of the information."
Mr. Zhao vigorously shook his head.
"There weren’t many insiders present yesterday, and it’s improbable that anyone of them would disclose such information. Mr. Liu, is it possible that after he chose a good location, he didn’t stay to stake out here but found a vantage point from which he could observe the situation on Qin University Road? After all, at the end of this road are two residential areas related to Qin University."
Liu Yongxin thought for a moment.
"Don’t speculate further. You shall take the team and visit the scene again, inspecting every possible location. Your theory seems plausible—spotting Zhou Ning’s car approaching would prompt the perpetrator to hide in the shrubbery of the garden and wait for the right moment to act.
And while you’re there, check the part of the fence connecting the residential area with the school to see if there’s any damage or traces left by these footprints. If we haven’t found any vehicle, it means we’re searching in the wrong direction.
Perhaps the perpetrator didn’t come from the direction of Qin University Road—after all, it’s a dead-end street resembling a skewered haw, with any incoming vehicles clearly visible. It’s not impossible to climb from the school to reach the residential area either."
Mr. Zhao stood with his mouth slightly open when Mr. Qu quickly opened the map, and everyone looked over. Following the map, as Mr. Qu began to pull down towards the campus area, Mr. Zhao immediately halted his movement.
"Hold on, we’ve always been thinking about how to get over there, but wouldn’t it be more convenient to go through Mount Fu? This way one would only need to cross the parking lot between two residential areas and circle to the south side next to the school fence. After climbing over, they’d reach the small garden, effectively avoiding all surveillance."
Mr. Qu glanced at it, drawing a line on the map.
"Indeed, that would evade patrol cars, and if one used binoculars from halfway up the mountain, any vehicle turning into Qin University Road would be spotted. It would take less than ten minutes to come down quickly from the mountain and be ready, even accounting for the time taken to climb the fence."
Mr. Zhao bit his lip, his demeanor becoming somewhat agitated.
"Coming from Qin University Road, there is an uphill slope and two speed bumps. Knowing Zhou Xiaozhou’s cautious character, he would have definitely driven slowly. The time he’d take to stop the car in the parking lot, grab his bag and clothes, and his habit of wiping the rearview mirror when alighting all add up—give him about fifteen minutes’ delay, and I think this possibility is even greater now."
Liu Yongxin gestured decisively.
"Then stop hesitating and rush to the scene to check it out. Peng, you go along too. On the way, can’t you also look up that document?"
