Shiller returned to the room, he didn't touch the sill, but instead gestured to Gordon with his eyes. Gordon moved forward and looked at the sill, commenting, "The sanitary conditions at Wayne Hospital are excellent, but this is just a common ward. The windowsill seems unusually clean, right?"
Shiller nodded, and Gordon moved closer. He leaned out to look down and noticed that the awning below had a framework. Though the frame was made of wood, it was nailed to the wall.
Clearly, the awning was already constructed during the building process. Any structure built by Wayne Enterprises was exceptionally well built. Hence, despite being just an awning, it could bear the weight of an adult male.
Gordon recalled the process he had just witnessed and then, as if suddenly realizing something, said, "I know why there were no wounds on the arm. Doctor Richard's arm was grabbing the window handle and hadn't been withdrawn when the dagger penetrated his heart. It wasn't that he didn't want to resist; he simply didn't have enough time."
Shiller nodded and said, "Detective, you should examine his wound more closely, especially the edges of the wound. There should be something different."
Upon hearing this, Gordon immediately went over to the body, knelt down and put on gloves. He examined the wound carefully, frowning as he said, "The upper half of the wound edge does seem a little different, but my forensic knowledge is limited…"
"You don't need to be an expert in forensic science. Did you notice that the cut at the upper edge is deeper than the lower part? Can you guess why?"
As Gordon was still thinking, Bruce started to speak.
"To prevent too much blood from dripping onto the sill, the killer did not extract the murder weapon when the victim was facing the window. He only pulled out the weapon after he had turned the body around."
"But then, the killer was standing outside the window, and the body had already slid down below the sill. The killer had to lean his upper body into the room, reach over the body's shoulder and only then could he pull out the weapon."
"When pulling out the weapon, the force was applied from above and behind the body, rather than directly in front. Hence the upper edge of the wound was more deeply injured."
Gordon shook his head and asked, "How in such a short time did you deduce so much?"
Shiller didn't come in; he was standing outside the window, looking down at the sill and said, "Next, we can discuss the killer's personality."
"You managed to deduce the killer's personality?!!" Gordon asked in surprise.
"From his series of actions, I think you can see that it was a premeditated murder. The killer was well prepared and may have practiced numerous times."
"Given that, he didn't immediately remove the weapon, he was swift in turning the body around, the blood might not have spilled onto the sill, but he still wiped it thoroughly inside and out."
Shiller touched the window frame outside the staircase lightly with his hand and looked at Bruce, saying, "If the patient hadn't returned so quickly, you would have had a free window cleaner."
Gordon rubbed the side of his cheek and asked, "What does this suggest? That he's a clean freak?"
"It indicates that he lacks confidence." Shiller shook his head and said, "Also, it indicates that he is likely a novice, or even more possibly, it was his first crime."
"Why?" Gordon asked. His thought process was already quite fast, which is why he could understand this technically complex case in such a short amount of time.
But the Gordon of now was still not good at reading the minds of criminals. Because in Gotham, most of the cases were gang fights or vendettas; there was no such twisting psychological puzzle to understand.
"Detective Gordon, do the theoretical knowledge you learned in the police academy always apply in reality?" Shiller asked.
After recalling a bit, Gordon answered, "Regarding criminal investigation, a fair amount is applicable. But in terms of civil mediation, it's almost completely inapplicable, we have to adapt to the situation."
"So, when you left the police academy, did you realize the difference between theory and reality?" asked Shiller again.
"At that time, I was quite naive. I felt that since I had good grades, the practice should also be good." Gordon thought for a while and said, "However, I did have doubts. But this is common sense, right? Everyone knows that theories can never perfectly match reality."
"This is precisely the contradiction the killer faces." Shiller lightly tapped on the window frame with the side of his finger, "Murder itself is an act against morality and the law. And to create such a premeditated murder case with deceptive intentions, from the investigation, planning to practice, it will definitely take a longer process than crimes of passion."
Gordon nodded, thinking that what Shiller was saying made sense. Crimes of passion were often driven by anger in the heat of the moment, making it difficult for the culprit to think about legality and morality.
However, for this premeditated crime, the timing may have taken several months. If the killer had even the slightest struggle or hesitation, he wouldn't have been able to persist this long and put his plan into action.
In a normal premeditated murder, the killer would attempt to conceal the truth to avoid punishment. But to coordinate everything so perfectly without any errors, clearly, it required practice.
"This isn't like practicing recitation or dancing. Each time he revises his movements, the killer would think about killing. Any normal person couldn't bear such immense moral pressure.", Shiller concluded.
Gordon's face grew more and more serious; he had to admit, Shiller was right.
Actually, he could tell that the motion Shiller just demonstrated wasn't very skilled. Furthermore, one hand was too forceful. If a real knife had been thrust into Bruce's chest, blood might have already splattered onto the window frame.
There was not a single drop of blood within the crack of the side window frame. This meant the killer executed that move perfectly, which undoubtedly required practice. Didn't it occur to him during each practice that he'd be holding a corpse?
Forgetting about morality, any trace of humanity should make one repulsed, disgusted, and fearful. This is human instinct. But the murderer, resolutely practiced that action to perfection.
"Such an indifferent, heartless, terrifying person," Gordon lamented. Shiller picked up from there, saying, "Or rather, we call them 'natural-born killers.'"
When Shiller breathed out the last few words, Bruce glanced at him but said nothing. Shiller carried on speaking.
"The greatest characteristic of this group is their cold-bloodedness. They won't feel sad at the loss of life. They take pleasure in hurting others and revel in the thrill of arbitrarily taking away lives of their own kind."
"While practicing for murder, they would not feel guilt or fear. On the contrary, the fantasy of taking other people's lives provides them a great deal of pleasure."
Gordon shivered, finding it hard to accept that such beings existed in the world.
Suddenly, Shiller changed the subject, "And this is why I say he is not confident. He has practiced so many times, yet he still doesn't trust his flawless execution. He worries it might leave a trace on the windowsill."
"Usually, the biggest gauge of a natural-born killer's perverse nature is their degree of arrogance. The more conceited and narcissistic they are, the more insane confidence they have in their evil deeds – something no one else can understand – the more difficult it is to apprehend them."
"I see," Gordon responded after some thought. "So, that's why some serial killers like returning to the scene, to watch police run in circles, as they're confident they won't be detected."
Shiller shook his head, saying, "All who return to the scene are unconfident."
Gordon's eyes widened. Shiller's view contradicted the mainstream belief that serial killers return to their crime scenes to taunt the police.
"Their returning to the scene is a reflection of their lack of confidence in their methods. They just need to ensure they didn't leave an extra clue behind, much like a student who checks his answers after an exam for fear of underperforming," he said.
"Or in other words, if they return, it means there are flaws in their methods. Just like top students who know they have calculated correctly would never bother checking their answers, whereas those less confident would."
Gordon glanced at Shiller, somewhat perplexed why the professor compared such a brutal murder to a routine examination. The analogy was fitting, but the casualness of his tone was chilling.
Shiller smiled, an indifferent and neurotic grin. Whenever he gave this smile, even Bruce would avoid his gaze.
Shiller gently touched the windowsill with his index finger, saying, "This murderer is like an insecure student who makes up for his insecurity by solving additional problems."
A trace of distaste crossed Shiller's face as he added, "Only mediocrities would resort to the exhaustion method to commit a crime."
Then, Shiller composed himself, looking at Gordon, saying, "Fortunately, he's one of those unconfident killers. So, if you stake out here, you should still have a chance to see him."
Gordon immediately started to move but Bruce stopped him and said, "You can't guard outside the hospital room. Anyone who sees you will know the police are here. You lead your men and pretend to examine the hospital's surroundings; I'll keep watch here."
"You're not thinking of installing a surveillance camera, are you?" For the first time that day, Shiller asked Bruce directly. Bruce was slightly taken aback, then shook his head, "Even the boldest killer wouldn't dare step into this room again. I plan to guard this entire floor."
"He might be bolder than you think," Shiller interjected, a cold smirk playing on his lips. "I forgot to mention, there's another kind of student, who, even though they're not confident about their answers, are very confident about their rank. They doubt their performance, but they doubt more that everyone performed poorly in a difficult test."
"So…" Bruce's eyes narrowed slowly.
Just then, a cacophony of sounds drifted in from outside the window. Bruce rushed to the window, with Shiller sidestepping. Bruce heard an uproar on the ground floor.
As both Gordon and Bruce dashed toward the door, they heard Shiller murmur,
"Maybe, he didn't return... because he never left?"
Just as Shiller was returning to the room, he heard the head nurse's scream from a room downstairs.
"Harley! Little Harley!! What happened to you?! Why is there so much blood all over you?!!!"