So apparently the NY address is a front for this group:
http://www.americanmuslimsvote.org/home.html
http://www.americanthinker.com/blog/2016/08/who_is_khizr_kahn_the_father_of_a_fallen_us_solder.html
americanmuslimsvote.org is run out of Khizr Khan’s home in Virginia. This is not a law firm.
KMKhanLaw.com is a law firm having a New York City address. Khizr Khan is a registered lawyer in New York state.