Court in Japan is actually very heavily prosecution-weighted. Once you're arrested by the police, it's assumed the cop had done their job and you're guilty. That's actually referenced in Phoenix Wright on why Phoenix had to do all the stuff to convince the court that his client isn't guilty, and there's also a Japanese tv series about a lawyer who specializes in overturning guilty verdicts, who almost literally do stuff Phoenix Wright does, investigating the actual crime and gathering evidences and the like, which is actually kinda weird because Japan also has law against admitting you're guilty to get lower sentence.
https://en.wikipedia.org/wiki/Criminal_justice_system_of_Japan#Conviction_rate
Btw, this is also the actual reason why lawyers are around. Lawyer's job is supposed to be making sure that the investigation is done properly.