Before graduating from the University of Illinois at Urbana-Champaign, Larsen worked at commercial stations WHZT-FM (105.9) and WZNF-FM (95.3) first as a production assistant and later, as air talent. He returned to Chicago in 1997 to accept a position at WMVP-AM (1000) working as both a producer and on-air contributor for Steve Cochran (Grumpy Old Men) and Talkmess with Kevin Matthews (Blink).
In the early 2000s, Larsen hosted middays at WZNX-FM (106.7) while working as the promotions director at the station. He later returned to the Chicago market to host evenings at WIIL-FM (95.1) while writing copy and voicing radio spots for TopHat Media Group. After a brief layover teaching English at Grayslake North High School, he began to write in earnest, making his first notable placement in What Fears Become with his short story, “Bast”.
Other short story sales followed, as did his novel, Losing Touch, which was named Best Horror Novel of 2013 in the Preditors & Editors™ Readers’ Poll. The story is about Morgan Dunsmore who, in the midst of a mid-life crisis, finds that he can walk through walls. Larsen’s follow-up, The Blackening of Flesh, was released in 2016, and tells the story of a high school graduate who finds out his house is haunted by Prohibition-era gangsters.