"Ether?" Han Fei stuck his head out the window and, just as Xu Mo had said, there were tire tracks on the empty ground below.
According to Xu Mo's theory, the perpetrator had used ether to knock out the little boy who had come to use the bathroom, then passed him through the window to an accomplice waiting outside, before casually walking out through the front door afterward.
That's why the police couldn't identify the real suspect from the surveillance footage - because the perpetrator never took the boy out through the front door.
He wasn't working alone; he had help. This was a gang operation!
Thanks to Xu Mo's explanation, Han Fei finally understood the perpetrator's method.
Looking at the small insect that Xu Mo pointed out - which had been inadvertently knocked out by the ether - Han Fei couldn't help but admire Xu Mo's meticulous observation skills, keen insight, and powerful deductive abilities.
Using just an unconscious insect found in the bathroom, he had unraveled the entire case and reconstructed the perpetrator's method. Such ability was truly impressive.
Even Han Fei, with his years of criminal investigation experience, was thoroughly convinced by Xu Mo. He certainly couldn't have reconstructed an entire case from finding a single insect at the scene.
"Amazing, you figured all this out just from this insect?" Han Fei asked after a moment of stunned silence.
"Yes," Xu Mo nodded. On this point, he wasn't lying - he really had understood the perpetrator's method because of the small insect.
"I could tell you had some ideas about this case when we were in the car earlier. No wonder you asked Chen Ke to drive back to the mall. You had already figured out about the ether and the perpetrator's method, and you wanted Chen Ke to return to the mall to find the insect knocked out by the ether?"
Xu Mo hadn't expected Han Fei to interpret it this way, but he met Han Fei's gaze and nodded anyway.
"Yes, that's right. Captain Han is indeed sharp to figure that out so quickly."
By now, Han Fei had completely understood.
Xu Mo had already formed his theory while they were in the car, and having Chen Ke drive back to the mall was just to verify his suspicions.
As for Xu Mo asking him to copy the surveillance footage earlier, it was probably because he already knew the perpetrator's method and wanted to screen the footage again to identify the culprit.
"You asked me to copy the surveillance footage because you already knew the perpetrator's method and wanted to review the footage to screen for the culprit, right?" Han Fei said with an expression that suggested he had it all figured out.
As he spoke, he took out his phone: "I've already copied the surveillance footage from the time of the incident. Let's watch it together."
I just wanted to get you out of the way when I asked you to copy the footage... Xu Mo smiled awkwardly and gave Han Fei a thumbs up: "Captain Han is indeed impressive. I can't hide anything from your eyes."
Hearing Xu Mo's flattery, Han Fei's face lit up with a smile.
"Haha, what's so impressive about that? I just figured out what you were thinking, that's all. It's just hindsight."
They watched the surveillance footage again on Han Fei's phone, using the process of elimination to rule out suspects.
"Not him. This person was inside for a very short time, just long enough for a quick bathroom break, no time for anything else. Plus, the wrinkles in his tucked-in shirt changed from when he went in, so he probably just went in to use the bathroom."
"Not this person either. He was inside for an even shorter time, and his hands were wet when he came out. He went in to wash his hands."
"We can rule out this student with the suitcase too. We already checked him out at Yangcheng University and cleared him of suspicion."
"..."
"It's him." When they got to the last person, wearing jeans and a white t-shirt, Xu Mo reached out and paused the surveillance video.
He dragged the progress bar back a bit and pointed at the phone screen: "Captain Han, look at his pants pockets."
"I see it," Han Fei nodded. "When this person went in, his left jean pocket was bulging but smooth, but when he came out, the pocket was disheveled. He probably had a towel in his left pocket. From the outline of his right pocket, it looks like he had a small bottle - when he went in, the bottle opening was facing up, but when he came out, it was facing down. That pocket probably contained the ether... It must be him."
Han Fei had noticed these details too.
Without a doubt, the suspect had to be this guy in jeans.
If their guess was correct, his jean pockets contained exactly what they needed to knock out the little boy - a towel and ether.
While reviewing the surveillance footage to screen for suspects, Han Fei and Xu Mo had no disagreement - they both believed the man in jeans was the most suspicious.
After identifying the suspect, the next step would be to make an arrest.
At this point, the police officers whom Xu Mo had sent away earlier returned after thoroughly checking the nursing room, women's restroom, and accessible bathroom.
"Detective Xu, Captain Han, we've checked everything. There are no other exits. What do you need us to do next?"
The officers asked if the two had any further instructions.
Han Fei waved his hand: "Next, we'll go back to the station to check the city surveillance cameras... and make an arrest!"
Hearing the words "make an arrest," the officers' faces showed confused expressions.
What arrest? Who were they arresting? Hadn't they not even identified the suspect yet?
Seeming to read the officers' minds, Han Fei briefly explained.
"While you were searching the other areas thoroughly, Detective Xu identified both the suspect and their method of operation."
The officers: "???"
How long had it been? The suspect had already been identified?!
Just a short while ago, everyone had been struggling with this case, and now suddenly, not only had the suspect been identified, but Detective Xu had even figured out their method?
Was this efficiency level even possible?!
After their momentary confusion, the officers burst out with their questions all at once.
"The suspect has been identified? How?"
"Who is the suspect?"
"How did they avoid the surveillance cameras?"
"..."
"We'll explain on the way," Han Fei gestured. "Detective Xu will walk you through the process while we head out to make the arrest. Let's move out."
Time was of the essence, and he had no time to explain to everyone - that would waste too much time.
In kidnapping cases, the police had to race against time; they couldn't afford to waste a single second, because every second delayed meant more danger for the victim.