Quote from Bulletin of the FBI,
"Marihuana is a more dangerous drug than heroin or cocaine. I am surprised to learn that certain police officers have been inclined to minimize the effects of the use of marihuana. They would, I am sure, be convinced that the drug is adhering to its Old World traditions of murder, assault, rape, physical demoralization, and mental breakdown. A study of the effects of marihuana shows clearly that it is a dangerous drug, and Bureau records prove that its use is associated with insanity and crime."