Maybe it's clear?

A few of them quickly returned to the crime scene and headed toward the trash can that Sun Zhijun mentioned. The street was sparsely populated, and the trash can was located in an alley next to the rental housing, emitting a faint sour smell.

"Liu Fu, you're best at finding details. Please take a look and see if there are any clues," Wang Yifei pointed to the trash can.

Liu Fu nodded, put on gloves, and carefully opened the lid of the trash can. Inside, it was filled with household garbage, with plastic bags and leftover food on top. Liu Fu reached in and poked around, quickly finding a deformed packaging box with a label faintly reading "Parent-Teacher Meeting Souvenir from Some School."

"Found it!" Liu Fu retrieved the box, carefully examined it, and said, "It's a bit damp, but you can still make it out. There's still traces of chocolate."

"Possibly containing toxic residues," Han Zijian nodded calmly. "Seal it for now and hand it over to professionals for testing later."

"Wait a minute," Zhang Yao approached for a closer look at the box, pointing to an inconspicuous corner. "There's a small red mark here. It looks like some kind of symbol."

Wang Yifei leaned in to take a closer look. It was a tiny mark resembling an eye with a crack in the center.

"This symbol doesn't look like something used by a regular chocolate brand," Wang Yifei frowned. "It seems more like... a secret organization's mark."

"An organization?" Xu Jiayin asked. "Could it be related to the perpetrator?"

"Highly likely," Han Zijian said gravely. "The mark on the packaging indicates the chocolate was deliberately delivered to their home. The perpetrator not only wanted to get close to the target but might also be using this mark to convey a message or instill fear."

"This indicates the perpetrator had been watching Sun Zhijun's family before acting," Wang Yifei clenched his fist, his tone colder. "They likely know their habits inside out."

"But there's no evidence yet to prove that the person who sent the chocolate is the perpetrator," Liu Fu said in a low voice. "This could just be a probing action or something meant to mislead us."

"Regardless, we can't ignore this clue," Xu Jiayin said softly. "When Sun Zhijun mentioned this box of chocolates, he noted that the taste was off, which is suspicious. If it contains toxins or some special ingredient, we can infer a relationship between the chocolate sender and the perpetrator."

Wang Yifei nodded, "Hand it over to the technical team of the Guard Corps for testing, and let's keep searching for other leads."

"One more thing," Zhang Yao suddenly said. "If the perpetrator knows their family so well, even calculating the exact time Sun Zhijun leaves home, it's possible they're still nearby. Could they be observing us?"

Everyone froze and immediately became alert, scanning their surroundings. The street remained quiet, but the stillness was unnerving. Wang Yifei took a deep breath and said solemnly, "Stay sharp. The perpetrator might be nearby. Let's split up and see if we can find any surveillance cameras or devices recording the surroundings."

"Got it." The others nodded and quickly dispersed, searching the alleys and buildings around the street.

A few minutes later, Xu Jiayin stood by a building and called out, "There's a surveillance camera here, possibly capturing the street during the incident."

Everyone gathered to examine it. The camera was positioned directly facing Sun Zhijun's front door, covering most of the area around it.

"Contact the Guard Corps to extract the footage and see if we can find anything," Wang Yifei said decisively.

They quickly contacted the technical team, handing over the chocolate packaging and surveillance video to the Guard Corps. Although the clues were not yet clear, the outline of the case was gradually piecing together.

---------------

The autopsy report arrived in the afternoon. It was compiled by the forensic team of the Guard Corps, detailing the victim's injuries and related hypotheses.

The report stated that the victim's wounds showed exceptionally professional stitching techniques, not something an average person could accomplish. The thread used was PDS II absorbable surgical suture, a high-end material mainly used in surgeries requiring precision stitching, such as internal organs or blood vessels.

Wang Yifei flipped through the report, frowning, "This thread isn't easily accessible to ordinary people, and the stitching is too professional. The perpetrator is likely connected to a hospital or medical institution."

"In other words, the perpetrator could be a doctor or someone in the medical profession," Han Zijian calmly analyzed. "This narrows down our investigation scope."

"A hospital," Liu Fu said softly. "We need to check nearby hospitals and see if anyone matches the criteria."

"That's right," Xu Jiayin agreed. "This specialized thread is usually purchased by hospitals in limited quantities. If we can trace its origin, we might find a lead."

They quickly headed to a large comprehensive hospital near District 7, the primary medical facility in the area, capable of performing surgeries. The hospital lobby was bustling, with patients and medical staff moving about.

They found the hospital's administrative office and explained their purpose. The person in charge, a middle-aged woman named Zhou, looked troubled after hearing them out. "We do use this type of suture, but it's distributed by the surgical departments, and I'll need to check the records to determine its usage."

"Thank you, Director Zhou," Xu Jiayin said gently, handing over a note. "Here's the batch information for the suture. Please help us verify it."

Director Zhou nodded, took the note, and reviewed it for a few minutes before saying, "This batch was delivered last month, primarily allocated to the cardiovascular and general surgery departments. I can provide the usage records, but they involve patient privacy. Are you only looking for the list of personnel?"

"Yes, we're focusing on the staff," Wang Yifei replied. "We need to identify who had access to this batch of sutures, especially those capable of working alone."

Half an hour later, they received a list of relevant personnel from the hospital, primarily doctors in the cardiovascular and general surgery departments. After cross-referencing and narrowing down the list, they identified several key suspects:

Xu Zhidong: A senior cardiovascular surgeon specializing in high-difficulty surgeries. Highly skilled but socially withdrawn, with average relations with colleagues.

Li Chengming: A general surgeon skilled in trauma stitching. Suspended a few weeks ago due to patient complaints but still active within the hospital.

Lin Lan: A cardiovascular intern with exceptional stitching skills. Recently exhibited unstable emotions and faced multiple patient complaints.

"These individuals all had access to the sutures, and some behavior raises red flags," Han Zijian observed while reviewing the list.

"Who do we start with?" Zhang Yao asked.

"Let's start with the suspended Li Chengming," Wang Yifei said solemnly. "He's not working but still active within the hospital, possibly giving him more time and opportunity to be involved in the case."

"Alright," the others agreed, heading straight to Li Chengming's department.