The American Civil Liberties Union reported in November 2013 that 3,278 Americans were serving life sentences for non-violent crimes. Many of these individuals are behind bars for charges related to drug possession or minor instances of drug trafficking.

The U.S. Bureau of Prisons reported in 2010 that the average annual cost of housing an inmate is over $28,200. Because of their life sentences, they are typically denied access to drug treatment, educational opportunities and even life-saving medical treatments. In short, they are essentially waiting to die.

Here are 15 inmates currently serving what many believe are unnecessarily harsh life sentences due to non-violent drug crimes often committed decades ago.