Darrin Joss, 45, was shot and killed on March 2, 2016, while working out in the gym of his luxury River West apartment building in Chicago. Surveillance footage captured the shooter approaching and firing at point-blank range as Joss exercised on an elliptical machine. The shooter, identified as 51-year-old Reggie Daniel, retrieved a gun from his apartment before the shooting and later claimed self-defense, alleging months of threats and harassment by Joss; the court found no evidence to support that claim and convicted Daniel of first-degree murder, imposing a 50-year sentence.

Joss had been born April 3, 1970, in Dubuque, Iowa, graduated from Dubuque Senior High School in 1988, and earned an Economics degree from the University of Iowa. He worked as a trader at the Chicago Mercantile Exchange and started his own firm, Joss Group Trading. Family remembered him as caring and compassionate; he was a fan of the Hawkeyes, Cubs, and Vikings and owned a dog named Hawki.