As far as I -- or anyone else -- can tell, Gilbert Vasquez and his fellow gang members killed Juan Lopez, without word or provocation, solely because they mistakenly thought he was a member of another gang. Oopsies. I agree with Justice Yegan that the shooting was for the benefit of a gang and that the enhancement was thus proper. That's why the dude was shot. That's why Vasquez will spend 50 to life in prison (or, more accurately, spend a long time, since he's not even eligible for parole for 15 years, and will be hard pressed to get out even then).
Parenthetically, I always knew that one way that you can mistakenly get shot in a gang area is by wearing the wrong colors -- e.g., red or blue -- or the wrong hat (e.g, an LA Dodgers cap). But I didn't know until today that another way you can get yourself shot is by wearing your hair the wrong way; for example, here, "in a style favored by [Vasquez's rival gang] as well as by his own." Interesting.
Fortunately, this is an area in which I've got very little to fear. Unless the Krazy Krowd 13 and 18th Street gangs tend to favor "short and balding" as the current style.