Excerpt from "A Community Response to Street Gangs" (1997), 
prepared by the Kansas City, Missouri Police Department Gang Squad

Parents need to understand that prevention is an important key to controlling gang activity within our community.  Learn the warning signs of gang membership in order to better direct your children away from involvement.  it is important to understand that many of the following indicators may be "innocent" by themselves, but when put together they may strongly signal gang involvement.

• Changes in the child's behavior.

• Not associating with long-time friends and being secretive about new friends and activities.

• Changes in hair or dress style and/or having a group of friends who have the same hair or dress style.

• Changes in normal routines with new friends, such as not coming home after school or staying out late at night with no explanation.

• Suspected drug use, such as alcohol, inhalants, and narcotic.

• Unexplained material possessions such as expensive clothing, jewelry, money, etc.

• The presence of firearms, ammunition, or other deadly weapons. 

• Change in attitude about school, church, or other normal activities.

• Discipline problems at school, church, or other attended functions.

• Lower grades at school or skipping school.

• Change in behavior at home-increase in confrontational behavior, such as talking back, verbal abuse, name calling, and a disrespect for parental authority.

• A new fear of police.

• Phone threats to the family from rival gangs (or unknown callers) directed against your child.

• Photographs or video of your child and others displaying gang handsigns, weapons, cash, drugs or gang-type clothing. Gang members, like all young people, are internet-savvy, so be sure to check social networking websites.

• Graffiti on or around your residence, especially in a child's room such as on walls, furniture, clothing, notebooks, etc. May also include drawings and "doodling" of gang-related figures, themes of violence, or gang symbolisms.  When looking over a child's homework reports, be alert for the letters "B" or "C" to be crossed out or inverted, or these same letters being used improperly, or to replace one another, such as the word cigarette being spelled "bigarette".

• Physical signs of being in a fight, such as bruises and cuts and secrecy on the child's part as to how they were received.

• A new found sense of bravery-brags that he/she are too tough to be "messed" with.

• Use of a new nickname.

• A new-found sympathy or defending of gang activity by your child.

• Tattoos or "branding" with gang-related symbols.