why that "gangster" segment is a thing
and gangsters/ gangs are really community members/builders well at-least they were until gangs became businesses(but for the sake of this argument lets not get into that )
every culture that immigrates here historically faces immediate persecution, quarantine and usually gets mistreated to a certain extent until they prove they are American enough to stay.
this cycle forces immigrants to group up and protect themselves because there is safety in numbers
this group gets a name and its members have interests.
how this gets perverted over time is dependent on environment and opportunity.
most immigrating cultures usually make a point to have their bilingual children appear as American as possible to avoid the constant racism within America from a small % of its citizens.