Whether marijuana is a “gateway” to the use of harder, deadlier drugs such as heroin is a matter of debate in the medical community.

While Afghanistan is by far the world’s largest heroin supplier, the United States and most of the Americas get heroin manufactured in Colombia or Mexico, according to the DEA and the United Nations Office on Drugs and Crime.

“One thing I always do when we arrest someone is look at their license ... You’ll see this beautiful girl who was healthy. Then I look down at this person and they are ravaged ... skinny, their eyes are withdrawn, undernourished. I will say to them, ‘Look, this is what you were.’ ” — Lawrenc…

Harmony King, a recovering heroin addict, reads a letter she wrote to her daughter Melody, explaining her past and her hopes for her daughter's future.