Beau Knapp's first on-screen appearance was in 2009, when he portrayed Luke in the short film "The J.H. Gunn Project." His next film appearance was significantly more high profile, when in 2011 he played the supporting role of Breen in the J.J. Abrams-directed film "Super 8." The film also starred Elle Fanning, AJ Michalka and Kyle Chandler, and focused on a group of teenagers that bear witness to a train accident and seek to unravel several subsequent mysteries in their town. He followed this effort up with a part in the 2012 thriller "No One Lives," about highway gangsters who kidnap a rich couple, and a role in the independent film " The Sunshine Shop" (2013). In 2015, Knapp appeared in the Liam Neeson action drama "Run All Night" about a hit man negotiating his fraught personal relationships, and was cast in Ang Lee's "Billy Lynn's Long Halftime Walk," alongside Garrett Hedlund and Steve Martin. The movie is an adaptation of a novel by Ben Fountain, about a group of soliders on furlough from the Iraq war. Knapp's father is producer Harry Knapp, who has worked on such projects as "Rescue Dawn" (2006), and "No One Lives"(2012).