Nationally, about % of all people placed in jail have been found to be under the influence of alcohol or an illegal drug at the time of arrest.

50 Percent.

Explanation:

The prison serves as a means of punishing offenders or those people who breaks the law, also the prison serve as a means of rehabilitating those offenders back into the society. However, it is not all people that actually sinned against the society that are actually behind bars, some people are just victims. Various types of people that one can see in prisons are the those people that forcefully have sexual intercourse with others, thieves, drug- traffickers and so on.

According to research conducted in the year 2008, about 2.1 million people in the United States of America are in prison for the possession of hard drugs. It was also recorded that about 50 percent are in jail because they were found under the influence of alcohol or an illegal drug at the time of arrest.