The Drug and Alcohol Impaired Driver is a guide for police enforcement of DUI laws. The author, a retired judge, explains the legal limits on stop, frisk, search and arrest in a clear and understandable way. The book presents an extensive list of drugs (both legal and illegal) that can impair driving and describes their effects. The latest developments on the legalization of marijuana and new research on the risk of driving under the influence of marijuana are included. Enforcement strategies, investigative techniques and tips for effective in-court testimony are covered in this exceptionally useful resource.