Here is a link to an interesting paper by Martinez and Lee on immigration and crime. They find that the widespread belief that immigrants' crime rate is higher than the rest of the population is incorrect. An excerpt from their conclusion follows.
"We can draw a number of broad conclusions from this review of immigration
and crime in 20th-century America. First, there are good theoretical reasons to
believe that immigrants should be involved in crime to a greater degree than
natives. For example, immigrants face acculturation problems that natives do
not, and immigrants tend to settle in disorganized neighborhoods characterized
by deleterious structural conditions such as poverty, ethnic heterogeneity, a preponderance
of young males, and possibly more criminal opportunities in the
form of gangs. Also, the cultural codes of immigrants may conflict with the
legal codes constructed by native groups. Despite these and other reasons to
expect high levels of immigrant crime, the bulk of empirical studies conducted over the past century have found that immigrants are usually underrepresented
in criminal statistics. There are variations to this general finding, but these
appear to be linked more to differences in structural conditions across areas
where immigrants settle than to the cultural traditions of the immigrant groups.
Local context appears to be the central influence shaping the criminal involvement
of both immigrants and natives, although in many cases, immigrants seem
more able to withstand crime-facilitating conditions than native groups."