Petroni worked in the early 1990s as a comedy writer and performer on Australian television, and appeared as "Psycho Bob", an American serial killer character, in The Big Gig and DAAS Kapital (with the Doug Anthony All Stars).
During his time at the AFI, he wrote his first feature film script, Till Human Voices Wake Us which he subsequently directed as a feature film starring Guy Pearce and Helena Bonham Carter, winning several awards for the script.
[2] Since his debut, Petroni has also co-written The Dangerous Lives of Altar Boys (2002), Queen of the Damned (2002) and Possession (2009), an English language adaptation of the Korean film Addicted.
[6] In March 2013, Screen Australia announced that it would be funding an Australian supernatural thriller, Backtrack, which Petroni would write and direct.
[7] In November 2017, it was announced that Petroni would be credited as an executive producer and creator for the Netflix thriller series, Messiah.