Can be applied to any of the detectives of your own choosing.
How do you get used to it?
He doesn't think he'll ever get used to it. He likes to think he does. He reckons it to the thrill of solving the crime, apprehending the criminal, and deeming the case closed. But at the end of the day – he lies down on his pillow and mourns.
He mourns for the sinner – the person who steals, who kills, who wronged others. He mourns for those who walked the wrong path, either by choice or forced by the hand of society whose eyes are covered from its own imperfections and the imperfection it created. Society isn't perfect, that's why justice exists. Not to condemn, but to guide the misguided back to the right path – even if it is behind bars.
He mourns for the dead – the person unjustly killed, wronged. There will be people who have committed grave sins, they deserved to die, but he detested that. No one deserved to die before their time. They especially did not deserve to be killed – a bad guy or not. He mourns for the dead who leave behind a family, a friend, an acquaintance, a person whose life was intertwined with their own – even for just a moment. He mourns for the dead who left behind someone who will wonder when they'll ever see each other again.
Does it ever get better?
It probably won't, but he learns to deal with that. He learns to control his emotions better but doesn't mean it hurts less. Just because he has control, doesn't mean he shouldn't feel it. He thinks it's better to feel than to have no feelings at all. Even if it hurts so much to see someone pass away in front of his eyes. Even if it hurts, knowing that even if he has solved the case doesn't mean the dead will come back to life.
He will probably never get used to it, but that's alright with him.
I'm sorry this is so angsty. I promise I'll update a happier one in the coming days (finally, quarantine has given me a chance to write fanfics again - kinda nostalgic as this was what I did during my homeschooled year)
Welp, see ya'll next time