Detection is a crucial component of reducing illicit drug consumption and controlling high-risk behavior of users. However, without testing, drug use by arrested suspects and convicted criminals is at best difficult to detect, because only about half of arrestees who test positive have admitted in confidential interviews to recent drug use. New research by the NIJ also documents widespread use of drugs among those arrested for serious nondrug felonies and, when added to other research, give reasonable cause to suspect drug use and to test for it among those coming into the criminal justice system. A policy of testing arrestees for drug use involves balancing the rights of the community to be protected from the risk posed by drug-using defendants against the rights of the defendant. Such a policy is reasonable, fair, cost-effective, and within the court's responsibilities both to protect the defendant's rights and to safeguard the public. 35 footnotes.