My Views in Brief
I frequently get asked by students to summarize my views on gangs, and what works to stop them. I give detailed information on this in my book, the 2 articles on my work with gang youth in Indian Country, and on the "Frequently asked questions" and "7 basics about gang prevention" tabs on the home page of this site. But the following would be my views in brief:

1. Boys: 85% of gang involved youth are boys. The great majority of boys who join gangs are there because they do not fit anywhere else. They generally are doing poorly in school and actively try to avoid it. The main reasons are emotional/behavioral problems, undiagnosed learning disabilities, and to a lesser degree difficulties at home. Since they are not involved in school and have no alternative means to feel good about themselves or obtain a sense of future, they spend their days with lots of free time, no structure and no legitimate means of making money. To the degree that a boy feels alienated from conventional success, is the degree to which they will become destructive, act crazy and take risks. Consequences do not matter to someone who feels they have nothing to lose.

2.  Peer pressure is not the reason kids join gangs. Gangs are groups of friends, and no teenage boy pressures another boy to be their friend. They bond because they have things in common and want to hang out together. Boys join gangs because this is where they find other boys whom they feel comfortable with and with whom they have things in common. Unfortunately, what they tend to have in common is a sense that they do not belong among regular kids and have no place in the regular world.

3. Most kids become gangs members with kids they have known since elementary school, and sometime in junior high they settle on this group as "their group". Remember, the teen years are about establishing an identity, and being outside the mainstream and in this gang, is where these kids feel they belong.

4. What works to both prevent and intervene with gang kids:
a) Give them something that allows them to feel they can belong somewhere besides the gang:
this can be a job, sport, hobby - anything that allows them to feel competent and comfortable with a different group of kids
b) Make school successful for them: this involves smaller schools, tutoring, looking at their disabilities and emotional problems, and being aware that school has usually been a place they failed.
c) Keep them busy! One of the dumbest things we do as a society is prevent these kids from participating in extra-curricular activities (they don't qualify because of grades, or schools for troubled kids are not allowed to have competitive sports or extra-curricular programs). They need to have structured and supervised activities and places to be after-school.
d) Help them with their addictions (if they have become drug users)
e) They needs skills and positive experiences that are concrete proof that they will have a future, and this will make them think twice about going to jail or engaging in risky behavior.
f) Don't let them get lost in big schools, or in the movement between detention, school, group homes, etc. Give them continuity and a sense that they are valuable and being looked after.
g) Do the above in the context of strong consequences and adult vigilence. All teens want to feel that the adults in their world have a plan for them to be successful, and are strong enough to structure their lives and protect them.
h) Don't expect gang youth to tell you what they need, and don't expect them to change over night. THESE  ARE TEENAGERS!!!  As an Indian Elder told an Indian gang youth at a meeting on the Pima reservation "You are kid, and your job is too rebel. Thats okay. But we are adults and our job is to raise you, and we don't need your permission to do that. You don't have to like what we're going to ask you to do, but you are going to do it."
That's the right attitude.

5. Age matters: A 10 year old who says he is in a gang is still a 10 year old and will respond to all the fun things that 10 year olds like to do. He will also drop the gang thing in a minute if he starts to like school,  and finds an activity that allows him to find different friends. A 16 year old is starting to worry about what he is going to do in life, and how to feel like a self-sustaining adult. A 20 year old is rationale and often easier to work with, but tends to come with lots of baggage, needs money to live, so illegal activities get more serious. The first thing to consider is not that the youth is or wants to be in a gang, but how old is this youth and therefore what needs are driving their choices and sense of place in the world.

6. What does not work: telling them all the bad things that will happen if they join a gang or go to jail. Remember, these kids are in a gang because this is the only place they find other's like themselves. If they had someplace better, they would go there. Gang kids already know that this life will lead to nowhere (just ask them). Simply lecturing or trying to scare gang youth will do nothing: creating opportunities for them, and helping them experience success in our world is what they (and all kids) need. This takes time, money, hard work and committment.