But it is not true and it is a myth perpetrated by those who want to promote the open borders agenda:

The findings in the second report (GAO-05-646R) are even more disturbing. This report looked at the criminal histories of 55,322 aliens that “entered the country illegally and were still illegally in the country at the time of their incarceration in federal or state prison or local jail during fiscal year 2003.” Those 55,322 illegal aliens had been arrested 459,614 times, an average of 8.3 arrests per illegal alien, and had committed almost 700,000 criminal offenses, an average of roughly 12.7 offenses per illegal alien

https://www.americanthinker.com

Loaded with facts and stats