Large prison units in particular use random drug tests. 2,500 or more inmates test for drug use, and half of these use random tests. Though each state establishes its own policies, random drug tests generally result in actions against inmates who test positive for drugs. These actions can include warnings, denial of visitations, transfers to higher-security prisons, and postponement of parole eligibility. Random inmate drug tests are widely used because they have proven to be an effective security tool for managing incarceration facilities.
Wardens find the data useful in detecting security breaches.
Random drug tests also serve as a deterrent, since inmates, visitors, and employees know that tests are regularly conducted. In addition, the results of drug tests can be compared across prisons to identify units with the most problems. The American Correctional Association reports that most states have found the costs of drug tests to be quite low, particularly if processed through existing state laboratories instead of private contractors. Keeping drugs out of prison also will protect the safety of prison employees and reduce the chance of employee-inmate collusion. North Carolina's program North Carolina provides an example of a cost-effective random inmate drug testing program.