Japanese law doesn’t require evidence to be presented for review by both parties. “SURPRISE!!! I have facts you weren’t aware of!” is very much a thing there.
The entire game was written to show how messed up the Justice System is there.
Japanese courts have a 99% conviction rate. In essence, if you are accused of a crime you are already considered to be guilty and it is up to you to prove otherwise if you can. Remember in the end of Persona 5, where the person who falsely accused you of assaulting them confessed to everything on national television but you were still in prison until your friends tracked down every witness and got them all the recant their testimonies individually? That was in no way exaggerated.
Also Japanese police have a 90+% rate of successfully arresting a “suspect” for every crime they investigate. At first this sounds really impressive, how they always track down the criminal, until you realize that they do it through a combination of refusing to investigate crimes which seem hard to solve or are likely to involve organizes crime or politicians (lots of “suicides” and “accidents” which are very blatant murder), and any time they do open a case but fail to figure everything out in the first day or two they just grab a convenient scapegoat (usually poor, frequently an immigrant or ethnic minority).
There are also very few restrictions on how long you can be “interrogated” for after arrest, or what they can do to you during the interrogation. Almost all the accused confess to everything… eventually. Regardless of whether they were actually anywhere near the incident in question.
Yeah no, death note was also about how fuck up japanese police are. The reason the death note causes people to have heart attacks if you dont put a cause of death is because thats the go to excuse cops use if they dont want to investigate a case or cant solve it fast enough. And giving the death note to the police chiefs son and then exposing that son to be a fuckin freak and mass murderer was very much extremely intentional. The japanese justice system is extremely fucked up
