This section focuses on structured criminal groups that coordinate illegal activities for profit. Case studies may include mafia-style organisations, gang networks, illegal gambling operations, smuggling rings, and transnational crime syndicates. The analysis explores leadership structures, operational methods, recruitment practices, and financial systems used by these groups to sustain criminal enterprises. Investigative approaches such as intelligence operations, undercover infiltration, and international cooperation are often highlighted in these cases. Understanding organised crime helps readers appreciate the scale and complexity of coordinated criminal networks and the challenges faced by law enforcement agencies in dismantling such organisations.