A treacherous dog

【Gunfight + Mystery-solving + Decisive Killing】
I had already been backstabbing the underworld, and now you're telling me I was planted as an undercover cop??? 
Dean looked at the boss with eyes that would not close in death, scratched his head, and could only take the opportunity to transform into Los Angeles' five-star good citizen—Detective Dean!
Ps:
There's nothing supernatural, but there is a dark world out of our ordinary reach, filled with assassins, thieves, and all kinds of bizarre cases...

North American Detective: I am Proficient in All Kinds of Gun Quick Draws

Seeing this familiar gesture, Dean realized An Bei had switched personalities again. It seemed the pressure he had put on An Bei was considerable, causing An Bei to not even dare face him with his normal demeanor. But this version of An Bei isn't well-behaved at all!

Dean, holding a gun, made way at the entrance. "Turn left and go straight. Your target is right there."

The assassin An Bei, his eyes emotionless, glanced at the gun in Dean's hand. Moving with a relaxed rhythm, almost like a dance glide, and with a backpack slung over his shoulder, he approached the passage and Dean.

As they crossed paths, Dean made no move.

His right hand, holding the gun, swung down hard like a steel pipe.

The assassin An Bei was on guard. However, trapped in the entranceway with his back turned, he could only raise his hand in a feeble attempt to block, even as several dark, short spikes shot out from his sleeve.

Chapter 97 Conclusion, New Case_1