Just for reference, I wanted to check on what fraction immigrants are of our overall population, what fraction of prisoners are illegal aliens, ... and I'm not sure the data you referenced is accurate.
According to Immigration: The Demographic and Economic Facts, Figure 2.4: Immigrants as a Percentage of the Population, 1850-1990 (you will have to scroll down to find Figure 2.4) the US immigrant population is actually lower now than it has been for much of the last 200 years.
I've seen estimates (eg: http://www.theamericanresistance.com/ref/illegal_alien_numbers.html ) that the number of illegals in the US may be as high as 28 million people (out of ~300 million US population) but that estimate is considerably higher than I've seen from other sources. The number I've seen most often for illegals is more like 8-10 million, but all these numbers are guesses.
According to http://www.gao.gov/new.items/d05337r.pdf the ''Criminal aliens incarcerated increased from about 42,000 at year-end 2001 to about 49,000 at year-end 2004.''
And: ''We estimate the federal cost of incarcerating criminal aliens totaled about $5.8 billion from 2001 through 2004''
I do not know how to reconcile some of these numbers. I suspect that some of the counts (eg: the 42,000 to 49,000 number) refer to prevalence figures (illegals in prison at a point in time) where the higher counts (50,000 plus) refer to incidence figures (numbers of incarcerations, with the possibility that an individual is incarcerated multiple times during a year).
Now, what is the denominator to use if we are calculating the proportion of the prison population that is illegal immigrants? One source: The Straight Dope: Does the United States lead the world in prison population?, Does the United States lead the world in prison population?: ''We've got roughly 2.03 million people behind bars, or 701 per 100,000 population.'' (As best I can tell, about 2/3 of that figure is in federal/state prisons and 1/3 in city/county jails, based on data at http://www.census.gov/prod/2004pubs/03statab/law.pdf )
Using those figures, if we have ~50,000 illegals in prison (from the gao report) and 1.4 million in prison (excluding local jails) (from the census report) then our prison population is ~3.6% illegals. That is a long way from 29%. I've seen unsubstantiated claims that the proportion of illegals in Federal prisons is ''greater than 25%'' (eg: http://usinfo.state.gov/eap/Archive_Index/Prepared_Testimony_by_John_M._Morganelli.html ) but I've never seen anything like source data that confirms it. Personally I'm inclined to be skeptical of unsubstantiated attention-grabbing numbers like that. I don't like getting my denominator and numerator from different sources, but I have not found any reliable source that quoted both figures.
Anyway, the point is this: I'm curious if there is any data to support the rather sensational claim that 29% of all inmates under the control of the Federal Bureau of Prisons are illegals. If the actual proportion of illegals in prison is substantially higher than their proportion in the population at large then you may have grounds to complain about an epidemic of crime caused by illegal aliens. If the proportions are similar then all it means is that they are just like the rest of us. I do not know the answer here, but based on what I've been able to find I'm extremely skeptical of the numbers you quoted.