beta
Even if he is the sole survivor and witness, let's be clear this detective is harassing the MC for *HIMSELF*.
(︶︿︶)＝凸
This is the case he can't let go, so he's willing to break the MC (who has already suffered 24 lifetimes of trauma) just to solve the case.
(╬￣皿￣)凸
Taking the MC & ML's dynamic out of the equation, the detective is still badgering a *MINOR*, visiting them at SCHOOL, without their guardian present AND asking them to relieve their trauma.
（￣へ￣）
Even if the detective gets some evidence from the MC, the defence could easily argue that the MC was so distressed from all the harassment he said what he needed to, to the get the detective to back off