It's sad that jin had to die but he was still a killer. He was mentally unstable and he followed the villains mostly because they were the only ones that accepted him (in a way this speaks miles of what is inherently wrong with the system in helping the most vulnerable irl) but the line between what is right and wrong has to be firm and killing people is that line.
Heroes need to make decisions in life threatening situations and jin was unwilling to stop even when asked and warned. It is a difficult situation to be in but decisions have to be made.
Just FYI, I am all for defunding the police lol this situation is fictional and should not be compared to real life situations, just to be clear. ヾ(❀╹◡╹)ノ~
When you kill people you stop loosing the right to be understood. It is sad what some people have to go through to survive, but killing is always a choice. Killing for survival is different to killing in the name of an ideology. Ideally no one deserves to be killed but when you become a danger to innocent lives, you loose your empathy card.