[citation needed] Before entering politics, Justin Brannan was a hardcore punk guitarist for the bands Indecision from 1993 to 2000 and Most Precious Blood from 2000 onwards.

The band’s messages focused on social justice, human rights, environmentalism, relationships, individuality and espousing straight-edge views against drugs, alcohol and promiscuous sex.

The song features a lyric ("For Those I Love I Will Sacrifice") wrote by Brannan when he was sixteen years old that fans across the world have turned into a tattoo.

[8][10] Most famously, an image of the tattoo was seen on the ribs of a 19-year-old US Army infantryman named Kyle Hockenberry being treated in a medevac helicopter following an explosion that cost him both of his legs and one arm.

[citation needed] Brannan served as the Director of Communications and Legislative Affairs for Council member Vincent J. Gentile, representing the 43rd district which includes Bay Ridge, Bath Beach, Dyker Heights and portions of Bensonhurst.

[24][25] In May 2021, a former aide to ex-City Councilman Vincent Gentile, Michael Bistreich, settled a lawsuit with New York City for $850,000 where he alleged Justin Brannan bullied him.

[26][27] In June 2023, 72-year-old Democratic District Leader Charles Ragusa filed an ethics complaint with the New York City Council alleging that Justin Brannan threatened him.