Police claim that once recruited into a gang a child's behaviour will change, either suddenly or gradually.
To be accepted by the gang he, or she, must adopt a defiant attitude towards authority figures and this can involve violent behaviour at school or at home. Because gangs use intimidation and fear to recruit new members, police say the child may become quiet and withdrawn, even secretive, about his or her activities.
There may also be references to the gang being his or her "new family", unexplained absences from home (some children have disappeared for weeks at a time) and a decline in school grades.
Children involved in gangs may truant, take up drugs, keep late hours and have large sums of money or expensive items that cannot be explained. According to the Chinese Liaison Unit at London's Charing Cross police station any references to the following gangs - SW (Shing Wo), 14K or 14K Tigers - could point to involvement in triad gangs.
These could be reinforced by possession of red Chinese "lucky money" envelopes "Lai Sze", references to his "Tai Lo" pronounced Dai Lo (Big Brother) or brothers and triad or gang poems among personal possessions.