A police officer, especially an experienced narcotics officer, would seize upon the level of specific information provided by the anonymous source as the basis to open an investigation on the suspect described by the informant. The hypothetical situation described is too detailed and too vast to ignore. Informants frequently wish to remain anonymous to protect themselves against violent retaliation by the individual or individuals about whom he or she is reporting, and the level of details provided is sufficient that his or her identity need not be known. It would also be considered by the police that the anonymous source is a competitor of the suspected drug dealer about whom he or she is contacting law enforcement, and is hoping that the police department will eliminate a rival for business in a particular neighborhood or community. In short, the credibility of a source that provided the amount of specific information suggested in the question would be considered very high, and his or her information would almost certainly precipitate an investigation.