The most disturbing recent trend is the growing availability and misuse of heroin, especially from Pakistan. Use of cocaine is also spreading. South American countries are the main sources, and the drop in price has made cocaine available to many more people. Marijuana is the most commonly used illicit drug. LSD and amphetamines are also used. The police drug squad focuses on those who transport and distribute illicit drugs as well as on suppliers. The drug squad is also active in prevention efforts through its dissemination of accurate information through talks to various organizations. The force's curriculum materials include a unit on drugs. A variety of agencies must cooperate to produce successful drug control and prevention activities. For the proceedings of the seminar of which this was part, see NCJ 104462.