Blue Bloods: Season 6, Episode 21

6 - 21: The Extra Mile

When a key eyewitness in a murder trial flees out of fear of retaliation, Erin and Anthony spearhead their own two-person manhunt to find him and convince him to testify. Also, Garrett tries to convince Frank to attend the Police Union party, and Danny and Baez take a closer look at a suspicious convenience store robbery.