Debuting in the 1996–97 comic book limited series Batman: The Long Halloween by Jeph Loeb and Tim Sale, she is introduced as a member of the Falcone crime family, who assists her father Carmine Falcone in unearthing the identity of the "Holiday Killer", a serial killer who had been killing Gotham City's citizens in correlation with holidays in the yearly calendar.

In the 1999–2000 limited series Batman: Dark Victory which served as a continuation of the arc established in The Long Halloween, Sofia is revealed as the identity behind the murderer known under the alias the Hangman, who had spent over a year targeting and eliminating various members of the Gotham City Police Department, notably in association with former district attorney-turned criminal, Harvey Dent / Two-Face, who ends up killing her during a lengthy confrontation with Batman himself.

The character made her live-action debut in the 2017–2018 fourth season of the television series Gotham, portrayed by Crystal Reed.

She also appears in the 2024 HBO television miniseries The Penguin set in The Batman shared universe, portrayed by Cristin Milioti.

Afterwards, Carmine was killed by Gotham's district attorney Harvey Dent, who became Two-Face after having his face splashed with acid, and Sofia fell out of the Falcone's penthouse window after being attacked by Catwoman.