"The Somali terrorist who stabbed a Canadian police officer and ran over four pedestrians a few weeks ago entered the United States through the Mexican border and was released by Obama’s Department of Homeland Security (DHS), allowing him to continue his journey north. The ISIS operative, Abdulahi Hasan Sharif, was ordered deported, an Immigration and Customs Enforcement (ICE) spokeswoman told various media outlets recently, but was released on an “order of supervision” and the feds never saw him again."

https://www.judicialwatch.org/blog/2017/10/somali-executed-canadian-terror-attack-entered-u-s-via-mexico/