Drugs are related to crime in multiple ways. Most directly, it is a crime to use, possess, manufacture, or distribute drugs classified as having a potential for abuse (such as cocaine, heroin, marijuana, and amphetamines). Drugs are also related to crime through the effects they have on the user's behavior and by generating violence and other illegal activity in connection with drug trafficking. The chart below summarizes the various ways that drugs and crime are related.

Drug-related offenses and drug-using lifestyles are major contributors to the U.S. crime problem and are the focus of this fact sheet.

The U.S. Department of Health and Human Services (HHS) conducts an annual National Household Survey on Drug Abuse (NHSDA) that asks individuals living in households about their drug and alcohol use and their involvement in crimes (see table 1). Provisional data for 1997 show that respondents arrested in the past year for possession or sale of drugs and driving under the influence had the highest percentage of illicit drug use in the past year. Past year illicit drug users were also about 16 times more likely than nonusers to report being arrested and booked for larceny or theft; more than 14 times more likely to be arrested and booked for such offenses as driving under the influence, drunkenness, or liquor law violations; and more than 9 times more likely to be arrested and booked on an assault charge.

The annual Bureau of Justice Statistics (BJS) National Crime Victimization Survey (NCVS) asks victims of violent crimes who reported seeing the offender whether they perceived the offender to be under the influence of drugs or alcohol. According to the 1998 survey, 30 percent of victims could not determine whether the offender was under the influence of a substance. Of those who could make a determination, about 31 percent reported that the offender was under the influence of alcohol and/or drugs.

The National Institute of Justice (NIJ) Arrestee Drug Abuse Monitoring (ADAM) Program measures drug use among arrestees by calculating the percentage of arrestees with positive urine tests for drug use. ADAM data are collected voluntarily and anonymously at the time of arrest in booking facilities in selected U.S. cities.

Data collected from male arrestees in 1998 in 35 cities showed that the percentage testing positive for any drug ranged from 42.5 percent in Anchorage, Alaska, to 78.7 percent in Philadelphia, Pennsylvania. Female arrestees testing positive ranged from 33.3 percent in Laredo, Texas, to 82.1 percent in New York, New York. Male arrestees charged with drug possession or sales were among the most likely to test positive for drug use, while female arrestees charged with prostitution, drug possession, or sales were among the most likely to elicit a positive test result. Males and females arrested for stolen vehicles, robbery, and burglary also had high positive rates. Test results further showed that opiate use demonstrated a positive correlation to polydrug use: of the individuals who tested positive for opiates, three-fourths also tested positive for another drug.

Data collected from juvenile male arrestees in 13 cities showed that, similar to adult arrestees, the highest positive rates were found in juveniles charged with drug sales or possession. Overall, however, juvenile arrestees were less likely than adult arrestees to test positive for drug use. For juveniles who did test positive for any drug use, marijuana was overwhelmingly the drug of choice. On average, half of the juvenile males tested had positive results for marijuana. In addition, it was found that juvenile male arrestees who were in school were less likely to test positive for drugs than those not in school. This was particularly the case for cocaine and methamphetamine.

By the end of 1998, State and Federal prisons housed two-thirds of the Nation's incarcerated population and jails housed the other third. From 1990 to 1998, the Federal prison population almost doubled, reaching 123,041 offenders. The State prison population also increased significantly between 1990 and 1998, from 708,393 to 1,178,978 inmates. At year-end 1998, the number of offenders in jails was 592,462, an increase from earlier. This number includes people who were awaiting trial and those whose sentences were 1 year or less.

In 1997 the U.S. Bureau of the Census conducted surveys of State and Federal prison inmates for BJS and the Bureau of Prisons. These surveys asked sentenced Federal and State prison inmates whether they were under the influence of drugs at the time they committed the offense that resulted in their incar-ceration. The percentage of Federal and State prison inmates who reported they were under the influence of drugs at the time of the offense varied across the major offense categories (see table 2). These same studies found that drug offenders and robbers in State prisons were those most likely to report being under the influence of drugs at the time of the offense. State prison inmates convicted of sexual assault and negligent manslaughter were among those least likely to report being under the influence of drugs. Federal prison inmates were less likely, with the exception of murder and weapons offenses, than State inmates to have committed their offenses under the influence of drugs.

Another dimension of drug-related crime is committing an offense to obtain money (or goods to sell to get money) to support drug use. According to the 1991 joint survey of Federal and State prison inmates, an estimated 17 percent of State prisoners and 10 percent of Federal prisoners reported committing their offense to get money to buy drugs; of those incarcerated for robbery, 27 percent of State prisoners and 27 percent of Federal prisoners admitted committing their offense to get money to buy drugs (see table 3). In 1997, 19 percent of State prisoners and 16 percent of Federal inmates said that they committed their current offense to obtain money for drugs. These numbers represent a slight increase from the 1991 figures.

Trafficking in illicit drugs tends to be associated with the commission of violent crimes. Reasons for the relationship between drug trafficking and violence include the following:

• Competition for drug markets and customers.
• Disputes and rip-offs among individuals involved in the illegal drug market.
• The tendency toward violence of individuals who participate in drug trafficking.

In addition, locations in which street drug markets proliferate tend to be disadvantaged economically and socially; legal and social controls against violence in such areas tend to be ineffective. The proliferation of lethal weapons in recent years has also made drug violence more deadly.

Although the number of drug-related homicides has been decreasing in recent years, drugs still remain one of the main factors leading to the total number of all homicides (see Table 4). According to the Federal Bureau of Investigation's (FBI's) Crime in the United States: Uniform Crime Reports, the number of homicides that occurred in 1994 during a narcotic drug law violation (such as drug trafficking or possession) or because of brawls influenced by narcotics totaled 1,450, whereas in 1998 this number was reduced to 795. Despite this decrease, murders related to narcotics still rank as the fourth most documented murder circumstance out of 24 possible categories.

The drug/crime relationship is difficult to quantify because:

• Most crimes result from a variety of factors (personal, situational, cultural, economic); even when drugs are a cause, they are likely to be only one factor among many.

• What is meant by "drug-related" varies from study to study; some studies interpret the mere presence of drugs as having causal relevance whereas other studies interpret the relationship more narrowly.
• Reports by offenders about their drug use may exaggerate or minimize the relevance of drugs; drug-use measures, such as urinalysis that identifies only very recent drug use, are limited.

The evidence indicates that drug users are more likely than nonusers to commit crimes, that arrestees frequently were under the influence of a drug at the time they committed their offense, and that drugs generate violence. Assessing the nature and extent of the influence of drugs on crime requires that reliable information about the offense and the offender be available and that definitions be consistent. In the face of problematic evidence, it is impossible to say quantitatively how much drugs influence the occurrence of crime.

This document is not necessarily endorsed by the Almanac of Policy Issues. It is being preserved  in the Policy Archive for historic reasons.