I do get The Shield vibe sometimes in Southland too but I know why.
It is the hand held shakey cam style that The Shield uses. When people are running and driving, the cameraman is running with them or in the car with them. When people in both shows are not moving around, the cameraman pans around the character. It's not a common method used in top shows and this makes it more noticeable. The fact both shows are cop shows and because both use this camera method it is easy to see the similarities.

I have to disagree. The style is completely different. One is a story about corruption and the other is about the personal lives of everyday cops. While both great shows, they are very different.