When John & Finch drop off Leon Tao, the building they are standing in front of is one of the oldest in NYC and connected with American History. In 1770, Samuel Fraunces, American patriot, resumed proprietorship of NYC's "Queen's Head Tavern", which housed a number of radical activities including meetings of the Sons of Liberty, the so-called New York Tea Party (1774), and meetings of the Provincial Congress of NY, which were attended at times by George Washington in the summer of 1776. Source: Fraunces Tavern Museum website.
The person of interest is a woman married to another woman. Same-sex marriage only became legal in New York State in 2011, the year before this episode was first aired, and nationwide not until 2015, three years later.
Guest stars Sharon Leal as Dr. Madeleine Enright and Julian Sands as Alistair Wesley. These actors both have connections to shows about Kryptonian heroes. Sharon Leal had a recurring role on Supergirl (2015) as martian M'gann M'orzz, and Sands guest starred as the reincarnated Jor-El on Smallville (2001). Jim Caviezel was briefly in talks to play Clark Kent/Superman in Superman Returns (2006).