I have received several requests to make recommendations on law enforcement gang information sources. I was also recently asked about the use of some textbooks on gangs in college courses.

So, here are some law enforcement gang sources and authors that I would recommend. I am unable to list everyone because I only have a limited space. I tried to give a varied mix of more recent textbooks, non-fiction books, Websites, and blogs. I'm going to organize this alphabetically by author.

Chris Blatchford is the best crime investigation television news reporter in Los Angeles. He is not one to let someone else investigate and interview players in the mean streets of Los Angeles, he does it himself. Because he has gone where others fear to go and interviewed characters others would not, he seems to capture the essence and issues missed by the mass media TV sound bites. He has won numerous awards and commendations, including several Emmy Awards and a Peabody Award for his investigation into the Italian Mafia's infiltration of MCA/Universal music and home video divisions. He has been honored by several law enforcement agencies and associations. He has been a friend of mine for many years. His most recent book is "The Black Hand: The Bloody Rise and Redemption of "Boxer" Enriquez, a Mexican Mob Killer."

(Editor's Note: Chris Blatchford will serve as moderator of a special roundtable on gangs at TREXPO West , Tuesday March 31, 5 to 7 p.m., at the Long Beach Convention Center in Long Beach, Calif. Admission is free to credentialed law enforcement and military.)

In "No Angel," BATF Agent Jay "Jay Bird" Dobyns' tells the story of "Operation Black Biscuit" and his three-year undercover infiltration of the Hells Angels Outlaw Motorcycle Gang . The Big Red Machine denies it, but Jay was eventually given his colors and made a member. This case took place here in my new hometown of Bullhead City, Ariz., (2001-2003). This undercover infiltration by several BATF agents and police officers was a nail biter from beginning to end. My LASD Team served the warrant at the San Fernando Valley California H.A. Chapter Headquarters in this case. The book is scheduled for release Feb 10.

A filmmaker and journalist, Gary "Rusty" Fleming is the president and CEO of Renavatio Productions . In 2006 he interviewed me for a documentary about the border drug wars. We have remained friends and information sources for one another ever since. Rusty lived in Mexico and researched his documentary, "Drug Wars-Silver or Lead" for three years. While making the film, he had unprecedented access to the Mexican drug cartels and the military Zeta killers that serve them. The result was a very graphic and hard-hitting film that tells the bloody truth about the border drug wars. Rusty premiered the documentary at TREXPO East last year, and the documentary also was the basis for a book, "Drug Wars-Narco Warfare in the 21st Century" in 2008.

Ramon A Mendoza, AKA "Mundo," was a well-placed member of the Mexican Mafia prison gang. He was a friend and confidant of "Godfather" Joe Morgan and the founding fathers of the gang. During an incarceration and trial for a double murder of rival Nuestra Familia members, hitman Mundo experienced a religious conversion. This was no fake "jailhouse conversion" but one that remains with him to this day. Miraculously the case against him and crime partner "Sailor Boy" was dismissed on a technicality. Filled with remorse and contrition to make right his many wrongs, he approached law enforcement to become a government witness within the Mexican Mafia. His self-published book on CD, "Mexican Mafia: Altar Boy to Hitman," available here would make an excellent movie. It is filled with insight and facts that only an insider could know about the early history of this notorious gang. Mundo's hope is to publish his book in paperback form to reach back into prison and give the truth to the prisoners who believe the dark myth of the Mexican Mafia.

Gabriel C. Morales was born in the Eastside Barrio of Yakima, Wash. Small by L.A. standards, it was nonetheless a tough neighborhood. Exposed at an early age to crime and violence, Gabe was familiar with the street gang lifestyle shared by many of his friends. He joined the Marines and was stationed in Southern California. When discharged he landed a job working at notorious Folsom Prison in California, where he dealt with many prison gang members. Several years later he returned to Washington and became King County's "Gang Specialist." Gabe founded the International Latino Gang Investigators Association (ILGIA) in 2002 and was the first president. He also has a training and consulting business called Gang Prevention Services . You can glean some of Gabe's wisdom and experience by reading his books: "Varrio Warfare: Violence in the Latino Community" and "La Familia-The Family: Prison Gangs in America" Gabe donates 10 percent of the income derived from the sale of his books to local programs to keep kids in school and out of trouble.

Det. Tony Moreno , better known to his friends and the gang members that he worked as "Pacman," was born and raised in Los Angeles. He retired from the LAPD after more than 30 years on the streets. Tony is an outstanding gang investigator and qualified expert in all areas of gang crimes and gang culture. He is a respected veteran gang cop whose observations and opinions should be taken to heart. His book, "Lessons from a Gang Cop," is more than just a book about gangs, it is the wisdom of someone who has done much more than most cops in the dangerous world of crime, drugs, and gangs and survived to tell about it. Talk about officer survival, Tony gives sage advice on not just how to survive physically, but mentally and emotionally as well.

Robert "Moco" Morrill : Growing up in some of the worst parts of Los Angeles in the late 1940s, Robert "Moco" Morrill's most impressionable teenage years were spent in the Ramona Gardens Projects, home of the "Big Hazard" gang. His exposure to some of the families that would later become founders of the Mexican Mafia prison gang proved invaluable in his later position working directly for the Chief of the Monterey Park Police as a special gang liaison officer. In the 1970s Robert Morrill became a member of the original multi-jurisdictional prison gang task force headquartered in a trailer behind the Monterey Park police station. His book, "The Mexican Mafia: The Story," tells the story of how this task force invented the tactics that would later be used so effectively against prison gangs. This is no academic study; it is a street cop's rendition of this exciting time. Unfortunately, it's out of print, but you can read his blog .

William Queen : Already a decorated Vietnam War veteran with the U.S. Army Special Forces, Agent William Queen spent 20 years with the BATF. His book "Under and Alone" tells the tale of his two-year undercover infiltration of the Mongols outlaw motorcycle gang. Playing the outlaw biker Billy St. John, Billy not only became a full patched member, but he rose to the position of secretary-treasurer of his chapter. My team had the privilege of booking and processing most of the suspects taken down in this investigation at the Pasadena jail. Billy Queen has been honored with numerous law enforcement awards, including the 2001 Federal Bar Association Medal of Valor, the Directors Award from the U.S. Department of Justice, the Robert Faulkner Memorial Outstanding Investigation Award from the International Outlaw Motorcycle Gang Investigators Association, The Metal of Valor from the International Narcotics Investigators Association, and the Distinguished Service Award from the BATF. His book "Under and Alone" is in production as a major motion picture scheduled for release in 2010.

Tony Rafael is the nom de plume of another writer friend. I first noticed him as he sat in the gallery of Criminal Courts Building courtroom taking notes as I testified in a series of murder cases in the 1990s. Sometimes the LA DA's Office would have young prosecutors listen to my expert gang testimony in these cases as sort of training, but this person appeared over and over again during several different trials. He even sat and took notes in the Mexican Mafia RICO trial at the federal courthouse. Finally, the dean of senior Los Angeles prosecutors, Anthony Manzella, introduced him to me as a writer who was working on a book about the Mexican Mafia and the Avenues Gang murders ( "The Mexican Mafia" ). You can buy it here. Tony Rafael also runs a blog called "In the Hat."

Sgt. Lou Savelli retired from the NYPD after 25 years in law enforcement and was one of the most decorated officers in NYPD history. He created NYPD's first citywide gang unit, CAGE (Citywide Anti Gang Enforcement). CAGE was awarded the National Gang Crime Research Center's Award for The Most Successful Gang Unit in the U.S. Lots of "Gang Experts" talk the talk or write about it, but Lou Savelli has actually had outstanding success in the enforcement and investigation of some of the most violent street gangs, drug gangs, and organized crime gangs in America, including the Latin Kings, Crips, Bloods, Cali Drug Cartel, and New York's Five Mafia Families. He has worked undercover amid gangs and was targeted for a "greenlight" (murder contract) by the gangs he fought. Currently, he is president of the Homefront Security Company . Lou's many books include: "Gangs Across America and their Symbols," "The Pocketguide to Graffiti," "The Gang Investigation Manual," and "A Proactive Law Enforcement Guide for the War on Terrorism." You can buy them here .

Ron Stallworth : Retired Utah Department of Public Safety Officer Ron Stallworth is the original "Hip Hop Cop." But before that this African American officer successfully infiltrated the local Ku Klux Klan chapter while working intelligence for the Colorado Springs (Colo.) PD. He carries a memento of that case, a KKK membership card signed by David Duke. Ron began writing about the Hip-Hop and Gangsta Rap culture when it first began in the early 1990s. He testified before the U.S. Congress and the Senate Judicial Committee on this subject. He has also testified in court as a gang expert many times. Currently Ron is a Professor teaching at a local college. Ron was interviewed by Davey D for the Thug Life Army program on Dec. 11, 2007, this interview is a must hear for anybody interested in Gangsta Rap. Ron has self-published several book on gangs and rap music, including "Gangster Rap: Music, Culture & Politics," "Significant Developments in Gangster Rap Music Since the Rodney King Uprising," "Bringin' The Noise-Gangster Rap/Reality Rap in the Dynamics of Black Revolution," and "Real Niggas: Gang Bangin' To The Gangsta Boogie in AmeriKKKa." Law enforcement officers can access these publications by contacting Ron at ronstall@aol.com.

Al Valdez : In the 1980s, I was teaching criminal justice classes at the Rio Hondo College in Whittier. One of my students was a young Orange County cop named Al Valdez. Even back then, Al had an unquenchable desire to learn more about gangs. Since then he has written several gang sociology books and was a former writer for Police Magazine's monthly "In the Hood" gang articles. Al is a nationally recognized authority on gangs and a consultant to the California and the United States Departments of Justice. He also received his Ph.D. a few years ago, so now I must now call my former student "Dr. Valdez." Al teaches at the University of California at Irvine. His book, "Gangs: A guide to Understanding Street Gangs," is a classic and used as a text in several colleges.

James Diego Vigil : A professor of social ecology at the University of California at Irvine, James Diego Vigil Ph.D. was formaly a social anthropologist and professor in the Department of Criminology, Law, and Society at the University of California at Los Angeles. He specializes in urban psychology and socialization and in educational anthropology. In my opinion most of the academic babble written and taught by social scientists who study gangs does not stand up to the practical test and the observations of gang investigators in the real world. We are required to read it because we will be asked about it on the stand but most of it is drivel. Vigil's work is an exception to that rule. I often taught with him at the LASD Advanced Officer Gang School. He is the most police palatable social anthropologist that I know. He does much of the work himself in the field with gang members in their natural habitat. I am listed as a contributor to his book, "Barrio Gangs: Street Life and Identity in Southern California." Other works of interest include: "A Rainbow of Gangs: A Cross-Cultural Study of Street Youth in Los Angeles," "The Projects: Gang and Non-Gang Families in East Los Angeles," "An Emerging Barrio Underclass: Irregular lifestyles among former Chicano gang members" (New directions for Latino public policy research) (out of print), and "Learning from gangs : the Mexican American experience" (out of print).

Ken Whitley: Retired Garden Grove, Calif. police sergeant, Ken Whitley's Website "Convicts and Cops" is an outstanding source for information and training on parolee contacts, security threat groups, gang tattoos, and gang case law. Whitley remains in contact with Mundo Mendoza and acts as a liaison in order to protect Mundo's new witness protection identity.

Richard Valdemar: I've often been asked if I have authored any books on gangs. I have not, not yet. But you can read about many of the gang cases I was involved in because others have written me into several books.

Going back to the mid 1970s, Dep. Jimmy Vetrovec, my partner and I are minor characters in the novel "Murder Children" (out of print) by the Edgar-winning mystery writer John Ball, who also wrote "In the Heat of the Night."

I also serve as your gang correspondent here on PoliceMag.com . And I have frequently contributed to the print edition of Police Magazine and Police Recruit. Here's two of my articles that you can view online:

I am also the technical advisor for the History Channel's very successful "Gangland" series  and I recommend any and all of the "Gangland" documentaries and the "Gangland" blog .