Dear kindly Sergeant Krupke,

You gotta understand,
It's just our bringin' up-ke
That gets us out of hand.
Our mothers all are junkies,
Our fathers all are drunks.
Golly Moses, natcherly we're punks!

—"West Side Story"

Back in the mid-1950s in New York City, "West Side Story" juvenile detective Sgt. Krupke had all the information he needed to work the local gangs, the Jets and the Sharks. This was because in the good old days gangs were a "turf oriented" local phenomenon. It was unnecessary for Krupke to confer with other cops in Los Angeles or Puerto Rico to learn about the gangs.

Today things are different. American street gangs have evolved, morphed, and mutated. Although turf claims and territory still have a part in their local conflicts, many gangs are now transnational with umbrella coalitions and virtually no boundaries. (Read "No Boundaries" by Tom Diaz.

No matter how small or large a town they work in, and whether they work urban or rural, gang cops need to know about and recognize the signs of criminal gang activity associated with national and international gangs such as Chicago's Folks and People, Los Angeles' Crips and Bloods, California's Sureños and Norteños, as well as Mexican drug trafficking organizations (DTOs), the Cosa Nostra, and even al-Qaeda.

Gang methods of operation and identifying signs and symbols will continue to morph and change. Sometimes there are also local influences on this migration and evolution. You can't possibly know everything about all of these gangs or keep up with all the changes on your own. You may also have stumbled on important information in your jurisdiction that needs to be shared with other gang units who work these same gangs in other jurisdictions.

I'm an old dinosaur. I first built my gang intelligence files in handwritten notebooks and intelligence cards. Years later, I was dragged kicking and fighting into the computer age. But today, gang cops must be familiar with the new communication technology, the Internet and social networking.

Unfortunately, there are pitfalls in this new technology. If you have not yet discovered this, I must tell you that not everything you find on the Internet is true. You must be positive that your sources for gang histories and intelligence are reliable. You don't want to be on the stand under oath pontificating on some gang facts only to be shown that your "facts" are false. This would probably not only result in a lost case, but also damage any future credibility you might have.

Your computer-based gang intelligence files can also be compromised by unscrupulous defense attorneys who can try to get the court to expose this data and its sources. Any flaw or minor typo could be used to attack the reliability of your intelligence files and your testimony. You must protect this valuable data.

By their very nature police agencies and investigators tend to be conservative and sometimes technologically challenged. But gang members have adapted to the new communication technology and many actually excel in these high-tech skills. Remember, today's gang members not only spraypaint their messages and mark out their turf on walls and sidewalks, they have also staked out gang turf in cyberspace.

Today's criminal gangs and their lawyer minions are also using counter intelligence tactics on the Internet. Today, if you are an effective anti-gang cop, you can bet that the bad guys will mine this new technology to use against you and even find out where you live. I suspect that some of the erroneous street gang misinformation on the Internet is planted by gangs to mislead unwary gang investigators.

There are many possible usable gang intelligence sources that have been built and have been defended against these pitfalls. There are city and county criminal gang data systems, state and federal law enforcement sources, and other reliable electronic sources available to you.

But these too present some dangers. In the recent past, we have seen that even vetted law enforcement officers have been compromised and have worked as double agents, disclosing information to the bad guys on criminal gangs and the active cases against them. I fear that this trend will continue and will always remain a threat.

Some federal agencies in the past have become incestuous with this type of criminal gang intelligence, fearing that "local" cops might be crooked. The resulting reputation of federal agents was often described by local gang cops when referred to this policy as the "Federal Alligator—You feed it, and feed it, but nothing ever comes out." I submit that in my 33 years experience, federal agents were just as likely to be corrupt as any local officer.

These dangers are inherent in the field of intelligence, and I suggest that even so we must err on the side of more open sharing of information. The federal agencies seem to have recognized this need and are becoming more cooperative. I believe that the exposure to local agencies involved in multi-jurisdictional federal task forces working against these large criminal gangs has had a positive effect on the federal agencies and made them more open to cooperation.

I recommend linking with some of the following gang intelligence sources for reliable information.

All gang investigators should join some professional association like the East Coast Gang Investigators Association, the California Gang Investigators Association, or the local state association. One of the best such organizations for training is the International Latino Gang Investigators Associatio n with chapters all over the U.S. and some internationally.

Nationally there is the FBI's National Gang Intelligence Center (for gang training and most wanted suspects)

The Federal Bureau of Investigation is also looking to add tattoos to its portfolio of human identifying characteristics, and it's reaching out to local law enforcement for information on how to do that, according to a request for information.

Another often overlooked source for jail and street gang information is the National Sheriff's Association

For a history of the Mexican Mafia in book form, " Mexican Mafia: Altar Boy to Hitman."

These are just a few of the reliable intelligence sources that I would recommend.