On a now-deactivated Facebook page, Mr. Alissa said he had moved to the United States in 2002, years before a vicious civil war turned millions of Syrians into refugees. The Syrian cities that some in his family name as their hometowns — Aleppo and Raqqa — became bombed-out battlegrounds and a haven for the Islamic State as Mr. Alissa and his siblings were growing up and starting businesses in the United States.
The Alissas were part of a tiny Syrian diaspora in Colorado. Arab-Americans make up less than 1 percent of the state’s population, and most of those who identify as “Arab” on census surveys say they are from Iraq, Somalia or Sudan. Just 324 Syrian refugees were resettled in Colorado in the last 40 years, according to data from the Colorado Department of Human Services.
Public records identify Mr. Alissa’s father as Moustafa Alissa, 62, and social-media profiles and interviews indicate that Ahmad was one of at least seven siblings. Several of his older brothers found a foothold in the restaurant business, opening food trucks that later grew into restaurants.
Records show that at various times, the Alissa brothers also ventured into a car-service business and — at one point — junk removal. A brother-in-law, Usame Almusa, a recent immigrant from Syria, filed corporate papers to form yet another restaurant business. It was not clear whether Mr. Alissa worked at any of the restaurants, though business associates said his older brothers put in long hours to make the enterprises a success.
The family moved at least three times over the past two decades, from the largely middle-class city of Aurora to an apartment in Denver to a rental in Arvada, where a former neighbor remembers family members sometimes stopping by to ask questions about the suburban chores of lawns and weeding.
Mr. Alissa had barely started at Denver South High School when the family moved again, and he had to transfer to first one high school, then another, in the nearby city of Arvada. They moved into their current home, a seven-bedroom, 7,400-square-foot house in a quiet subdivision, in 2017, according to public records, and paid $634,000. One of the older brothers, Ali, 34, is listed as its owner.