I want to always be in control of my emotion, be someone who has strong control of it like Bob Ross. Is there even a book for it?

So last night I watched this video on YouTube, about police officers responding to a trespass call. There was this man on his 60s, going batshit crazy on a heart clinic or some clinic I don't know. He freaked other patients and the nurse, so they decide to call the police to kick this guy out. Well the man is extremely agitated, shouting and cursing, what you expect is for the police to just shout back or straight to drag him out by force because this old man isn't making any sense and he's annoying as hell. But this one police officer is just unnaturally calm, like Bob Ross level of calm. I've never heard the line "you're under arrest" any softer than this. He never raised his voice, he never antagonize the suspect, he sounds sincerely want to help the suspect to get out of this situation. Although it resulted in the suspect being forced to get out of the clinic, the effort the cop gave to try to sort it out peacefully is still amazing to watch.

That video made me think whether that level of emotion control is a trait or a skill. I asked chatgpt and apparently it's a skill, and Bob Ross's calmness is also "a master-level of interpersonal skill". So is there a book for this?