Thanks to CIS, which has published a useful Google Map of immigrant killers released by Obama:
The 169 aliens with homicide-related convictions who were freed by ICE in 2013 were booked out of detention facilities in 24 different states, with the largest number in California, according to information provided to Sen. Chuck Grassley (R-Iowa). ICE records show that these convicted killers were associated with 96 different cities and towns across America. The city with the largest concentration was Miami, with seven convicted murderers freed by ICE, followed by Los Angeles with six.
A Town Near You? ICE Reveals Locations of Convicted Murderers It Freed, By Jessica Vaughan, August 22, 2014
Unless the immigrant killers also committed sex crimes, however, there's no database of exactly who and where they are.
And of course, that's only the killers—the US Government released 36,000 criminals whose own governments didn't want them back, because President Obama is unable or unwilling to make them take them back.
“This would be considered the worst prison break in American history, except it was sanctioned by the president and perpetrated by our own immigration officials,” said Rep. Lamar Smith, Texas Republican. “The administration’s actions are outrageous. They willfully and knowingly put the interests of criminal immigrants before the safety and security of the American people.”
Government Releases 36,000 Illegal Alien Criminals, By Brenda Walker on May 13, 2014