That's the heart of it, right here.
3 seconds sound clip from the Training Day (2001) movie soundboard.
You can hear this line at 00:49:47 in the Blu-ray version of the movie.
Quote context
[...]
- You got to decide whether you're a wolf... or a sheep.
- Get your ink or... go give him a hand.
- What are we doing going in here, man? We'll get killed coming in here.
- Ah, you know about this place, huh?
- Yeah, it's the jungle, right?
- They say don't come in here with anything less than a platoon.
- That's the heart of it, right here.
- Yeah, a lot of murder investigations lead right here.
[...]