One basic way that drug abuse and crime are connected is obvious: abusing a drug requires you to be in possession of it, so the drug abuser is committing a crime simply by having it. Actually, though, there’s a broader way in which drug abuse is tied to crime: substance abuse is common among people who disregard the law. According to statistics from the National Council on Alcoholism and Drug Dependence (NCADD), about 3 in 5 people test positive for illegal drugs at the time of their arrest. How many drug addicts are in prison? That requires combining two sets of statistics. NCADD data indicates that almost half of people who are incarcerated in the United States can be medically categorized as addicted to either illegal drugs or alcohol. Looking at those numbers alongside figures from the Prison Policy Initiative that show the total prison population at 2.3 million, we can derive that the total number of addicts incarcerated in the United States is close to 1.15 million. However, other research, from the (nonprofit, nonpartisan) National Center on Addiction and Substance Abuse, reports that the number is higher: 1.5 million inmates – 65% of the total incarcerated population.