Canadian filmmaker, genre screenwriter based in Los Angeles. Co-writing credits with frequent collaborator Adam Robitel include the psychological horror hit The Taking (2014), Paranormal Activity: The Ghost Dimension (2015) for Paramount Pictures, and an upcoming supernatural thriller for Sony produced by Sam Raimi. On the television side, Heffernan and Robitel are developing an original horror series with Darren Aronofsky's Protozoa Pictures.

Gavin is also known for directing experimental visual works, primarily timelapse, most notably featured in The Rolling Stones' 2015-2016 concerts, the 2016 Roger Waters tour, and Paul Simon's 2018 Homeward Bound Farewell Tour.

An alumnus of McGill University and the American Film Institute, Heffernan first hit the independent scene by writing, directing and starring in his micro-budget feature film Expiration (2003). Catching the attention of Variety, Film Festival Today and Ain't it Cool News, the $10,000 Montreal feature took Grand Prize at the 2004 Canadian Filmmakers Festival in Toronto and was later named "the first major work of the Student-DV New Wave" by The Film Journal.

Heffernan's experimental timelapses have been featured on Virgin America, BBC Earth, five seasons of Bravo's first scripted show Girlfriends' Guide to Divorce (2014), and many other press and TV outlets, including TIME Magazine, CNN, National Geographic, CBS News, and WIRED,among others. His shots have been used in Science Channel's Alien Encounters (2013) series, Travel Channel's Trip Flip (2012), and the celebrated LGBT documentary Matt Shepard Is a Friend of Mine (2014).

Heffernan has also directed and produced many successful short and experimental films. Premiering at the 2008 SXSW Film Festival, his unconventional anti-war film Grand Wheel (2008) played more than forty festivals in over fifteen countries and was presented with the Silver Bear at the 37th Festival of Nations in Austria, Best Cinematography at the 2008 Canadian Filmmakers' Festival and Best Experimental Film at the 2009 Oxford Film Festival. Heffernan's subsequent collection of experimental HD Short Films titled Devolution (2010) won an Audience Choice Award at the 2010 Hollyshorts Film Festival in LA. The sequel, a sci-fi throwback about UFOs attacking earth, Devolution: Reckoning (2011) was also a popular draw, premiering at the Festival Nouveau Cinema in Montreal and playing over fifteen subsequent festivals.