Huh?
The victims were said to have been a previous employer of the suspect before he was terminated a couple of years ago.
In 2005, he invaded the home of another trucking company owner (that had also previously terminated) and threatened to kill the owner and his family. He was convicted here and served 8 years.
There's no mystery. The suspect is a revengeful, disgruntled ex-employee with a history of similar violence against former employers.
I dunno... seems the common denominator here is trucking firms and not the national origin of the victims. Really not understanding OP's inquiry. MOO