[5] Larsen has covered international and domestic conflict, including stories about waterboarding, ebola outbreaks, drug trafficking, Boko Haram, Somalia, and the militarization of the Arctic.

He initially attended the United States Naval Academy where he played water polo, but he transferred to the University of California, Santa Cruz after two years.

[10][11] Larsen‘s career in journalism began in 2005 when he joined Current TV, a cable channel created by former Vice President Al Gore.

[12] Larsen, who had previously been waterboarded during military survival training told the interviewer the technique induced panic and felt, "like having a hot coal in your chest that you can't get out.

[16] In 2010, Larsen joined CNN as a correspondent for the Special Investigations and Documentary Unit covering the drug war in Mexico, the floods in Pakistan and WikiLeaks.

[3][8] As a producer Larsen worked on US Navy Pirate Hunters, a one-hour special for Spike TV,[17] and Lockup, the MSNBC show about life in an American prison.

[20][21] In 2019, Larsen appeared on The Fighter and the Kid podcast with Bryan Callen to discuss his career in journalism, including being waterboarded on TV and being embedded in Nigeria.

[22] Larsen created and served as the executive producer for the 2020 Netflix documentary series The Business of Drugs, which tracks the economics of the international narcotics trade.

[24] In addition to serving on the board, Larsen has deployed with Team Rubicon on humanitarian missions to Pakistan and the Philippines to aid those affected by natural disasters.

[26] On June 6, 2018 Larsen and a group of current and former SEALs recreated the original D-day mission of the U.S. Navy Combat Demolition Units, swimming seven miles across the English Channel followed by a 30 kilometer march from Normandy to Saint-Lô.