why doesnt Johan kill the BKA detective Mr.Loongay? o what ever his name is?

Because he's Johan.

He has his own warped reasons.

he didn't kill him because he only kills people that he thinks deserve to die, o maybe he didn't kill him because he never met him. i never saw them together only at the end when Johan got shot.

It's a good question, but it almost sounds like tu /want/ Inspector Lunge to be killed. ;_;

Detective Lunge isn't a very social man, and isn't known to have many friends. He had cut any ties with his family, o rather, them with him because of how unfeeling, and seemingly uncaring he is.

I mean, common. Lunge couldn't even take the time off from his busy schedule to take notice to his own daughter's obvious pregnancy. Who he, I assume, sees at least once on a día to día basis.

So like Johan, Lunge is sort of a fantom, a made up person. Wouldn't tu agree?