The detention of a Kansas father of three who has lived in the U.S. for three decades highlights what experts say is the extraordinarily complicated nature of immigration law — and how much can change from one administration to the next. Immigration experts said the path towards citizenship can easily get derailed by what appear to be minor infractions, which may have contributed to the seemingly out-of-the blue detention of Syed Ahmed Jamal last month. Jamal, who is from Bangladesh, was about to take his daughter to school on Jan. 24 when U.S. Immigration and Customs Enforcement (ICE) officials showed...