those judged to be guilty are sentenced to jails or prisons. At each stage of the criminal justice process, the data record is incomplete, and there is rarely any information on immigrant status beyond a simple measure of foreign birth or citizenship. The short answer to the underlying question is that it is difficult to draw any strong conclusions on the association between immigration and crime.

Crime measurement is particularly troublesome for illegal immigrants. Immigrants may be apprehended by federal, state, or local authorities for criminal acts, but many illegal immigrants are apprehended by the Border Patrol and other enforcement officers of the Immigration and Naturalization Service (INS). Many illegal immigrants who are apprehended by Border Patrol agents are voluntarily returned to their home countries and are not ordinarily tabulated in national crime statistics. If immigrants, whether illegal or legal, are apprehended entering the United States while committing a crime, they are usually charged under federal statutes and, if convicted, are sent to federal prisons. Throughout this entire process, immigrants may have a chance of deportation, or of sentencing that is different from that for a native-born person.18

Nativity and immigrant status can be assessed for prison inmates, however; it is possible to ask inmates about their place of birth as well as to validate their responses by checking with administrative records. Such information is available for federal and state prison inmates in 1991, when prison records were compiled by prison officials for citizens and noncitizens by their current offense and such demographic data as age, sex, and race/ethnicity. We use these inmate data to calculate rates of crime per 1,000 males, aged 18 to 54 years, for citizens and noncitizens (see Table 8.6).

Table 8.6 displays five major categories of crime: violent offenses, property offenses, drug offenses, public order offenses, and other. The first two columns report crime rates for citizens and noncitizens. The third column shows the ratio of the noncitizen crime rate to the citizen rate; values greater than 1.0 indicate that noncitizens have higher crime rates than citizens and values less than 1.0 indicate lower rates.19

One finding that is clear from this table is that noncitizens are more likely to be in prison for drug offenses, especially possession of drugs. Almost one-fifth of prisoners serving sentences for drug offenses are noncitizens, even though


A related measurement issue concerns information on immigrant status. Except data on noncitizens in the federal criminal justice system, we lack comprehensive information on whether arrested or jailed immigrants are illegal immigrants, nonimmigrants, or legal immigrants. Such information can be difficult to collect because immigrants may have a reason to provide false statements (if they reply that they are an illegal immigrant, they can be deported, for instance). And the verification of these data is troublesome because it requires matching INS records with individuals who often lack documentation or present false documents.


Noncitizens may have had fewer years residing in the United States than citizens, however, and thus less time in which to commit crimes and be apprehended. Hence, incarceration rates do not necessarily reflect differences in current crime rates.

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