There's been some girl-on-girl crime here.

4 seconds sound clip from the Mean Girls (2004) movie soundboard.

You can hear this line at 01:11:19 in the Blu-ray version of the movie.

Quote context

[...]

- Okay. Everybody, close your eyes.

- All right. I want you to raise your hand if you have ever had a girl say something bad about you behind your back.

- Open your eyes.

- Now, close your eyes again. And this time, I want you to raise your hand if you have ever said anything about a friend behind her back.

- Open them.

- There's been some girl-on-girl crime here.

- Okay, so what we could do today is a couple exercises to help you express your anger in a healthy way.

- Let's start over here.

- Ms. Norbury had us confront each other directly about the things that were bothering us, and it seemed like every clique had its own problems.

- You've been acting really stuck-up ever since you switched to shortfielder, and Dawn agrees with me.

[...]