The second phase of the DPI began in 1995 and will continue until 1999. Twelve teams are helping local areas support drug prevention projects and are assessing what approaches, targets, and settings can have a positive effect on knowledge, attitudes, and behavior related to drug use. Research on the size of the drug-using population, costs associated with problem drug use, and types and impacts of arrest referral schemes is being conducted. Findings to date indicate arrest referral schemes that put problem drug users in touch with treatment agencies are effective in reducing drug and drug-related crime. The following essential ingredients of arrest referral schemes are identified: proactivity, working style that wins the respect and trust of users, capacity to provide ongoing support, appropriate treatment services, and adequately funded treatment services. Recommendations are offered to assist others who want to establish arrest referral schemes. Appendixes contain forms used to collect research data. 26 references, 7 tables, and 9 figures