"In March 2000, Congress made public Department of Justice statistics showing that, over the previous five years, the
INS had released over 35,000 criminal aliens instead of deporting them. Over 11,000 of those released went on to commit serious crimes, over 1,800 of which were violent ones [including 98 homicides, 142 sexual assaults, and 44 kidnappings].
"In 2001, thanks to a decision by the Supreme Court, the
INS was forced to release into our society over 3,000 criminal aliens [who collectively had been convicted of 125 homicides, 387 sex offenses, and 772 assault charges]."
Up to a third of the U.S. federal prison population is composed of non-citizens, according to Federal Bureau of Prisons statistics - but not all non-citizen prison inmates are illegal aliens.
As to the "hard-working" claim, CIS notes: "The proportion of immigrant-headed households using at least one major welfare program is 24.5 percent compared to 16.3 percent for native households."
"The U.S. Justice Department estimated that 270,000 illegal immigrants served jail time nationally in 2003. Of those, 108,000 were in California. Some estimates show illegals now make up half of California's prison population, creating a massive criminal subculture that strains state budgets and creates a nightmare for local police forces."
http://archive.newsmax.com/archives/ic/2006/3/27/114208.shtml