Shiller, sitting in the interrogation room, indeed wasn't in a hurry. Because this time he really was just passing by. He believed that the upright Director Gordon would certainly clear him—unless Shiller's words infuriated him to death.
It was obvious that Gordon was already smoking with anger. But precisely because he's a law-abiding good person, he really couldn't do anything about Shiller. Because right now he's only a suspect, not a criminal. Even if the suspicion is unprecedentedly high, without a court trial, there's room for exoneration, and he cannot be treated as a criminal.
Now, regarding various crimes in Gotham, Gordon already had a very keen intuition. He felt that this case wasn't done by Shiller, but there was no reason to explain why he appeared at the crime scene.
Can it really be because he used to be a cleaner?
Here, a slightly absurd question must be discussed—if a person committed murder and didn't clean up the crime scene, while a passing cleaner tidied up the scene, is the cleaner guilty?
In the maritime law system, such behavior is usually charged with two offenses: one is "harboring the perpetrator," and the other is "tampering with the crime scene."
But actually, it's hard to establish either charge. To accuse of harboring the perpetrator, a premise is that the two conspired in advance. For example, the murderer hired the cleaner, or they conspired to divide the tasks. If the accused can prove there was no connection between them, such an accusation cannot be made.
The premise for "tampering with the crime scene" is that the person knew subjectively that it was a crime scene. And only the police can identify a crime scene. That means, only after the police arrival, if he still cleaned the crime scene, can "tampering with the crime scene" be charged; otherwise, it cannot be established.
In other words, assuming Shiller isn't the murderer, then he and Victor brought a heap of cleaning tools and cleaned part of the crime scene, making it difficult to convict them.
So how can it be proven that Shiller isn't the murderer?
The maritime law system generally follows "presumption of guilt." In other words, the police and court both assume the suspect is guilty, and the suspect must find ways to prove himself innocent, as often heard in comics and TV shows as "exoneration."
Actually, Shiller doesn't have very strong evidence to exonerate himself.
From the motive aspect, his emails contain the opponent's threatening emails and the address notification email, already clearly indicating the conflict between the two parties, which is very unfavorable evidence against him.
From the capability aspect, unless the body type disparity is too significant, one wouldn't typically be deemed incapable of committing the crime.
From the result aspect, he and Victor both appeared at the primary crime scene and couldn't produce an alibi. Due to their arrival time being too close to the victim's death time, it's hard to use the time difference to prove it wasn't them.
In summary, all kinds of evidence are very unfavorable to Shiller. If he really didn't do it, then he shouldn't have stayed at the crime scene. Because once caught by the police, there aren't many arguments left to escape suspicion.
But Shiller's calm demeanor made Gordon realize he surely had something to rely on. Just as Gordon was guessing whether Shiller had done something else, another police officer walked in and whispered a few words in Gordon's ear.
Gordon first frowned but quickly pressed his lips together, looked at Shiller somewhat helplessly, and left the room.
Shiller knew what called him away. The police interrogating him said Lina had reported three people, two professors had already been brought in, and the remaining student was Harley. At this time, she should also be brought in by the police.
Actually, whether from psychology or criminal investigation, the best way to exonerate oneself isn't self-proofing, but attacking others.
The case involving Shiller is difficult to self-prove innocence. But causing trouble for the person providing testimony, rendering their testimony invalid, makes it much easier to avoid substantial accusation and achieve exoneration.
Shiller was completely unflustered and cooperated by coming to the police station, precisely because he knew that the best way to prove he isn't the murderer is to catch the real culprit.
Lina, who provided testimony, has an alibi for tonight's murder case but not for the bassist's disappearance case.
She claimed to have seen Harley and two professors killing, but that's just her subjective statement. The objective reality is, she also showed up at the rehearsal room late at night and disappeared for the whole night, with no one knowing where she went.
If she says someone killed in the rehearsal room, she herself isn't entirely without suspicion. In fact, her suspicion is the greatest.
Because, compared to Harley, her relationship with the bassist was closer. Everyone in the ensemble has seen them in a dubious pulling and tugging manner and participated together in the Brainiac support group.
Moreover, she can testify against the three, and the three can naturally unite against her. The testimonies corroborating each other among three people are much more forceful than one's subjective narration.
In the absence of other evidence proving the other party's murder, the suspicions of both parties are equal. Therefore, Lina's claim about hearing Shiller and others scheming to kill tonight is unreliable, as it might be her framing after committing murder.
Once the witness's testimony becomes unreliable, and direct evidence couldn't be found at the crime scene, the probability of successfully establishing charges becomes very low. Exoneration becomes easy.