Daniel Horkheimer, 29, was shot and killed at his home in the St. Louis Place neighborhood of St. Louis, Missouri, on the morning of August 11, 2007. He was working on renovations to the house he shared with his wife, Courtney, and their dog Ivan, when an unknown assailant approached and opened fire; the shooter fled the scene. The St. Louis Police Department investigated and sought witnesses and evidence, but no suspect was identified and no arrests have been announced. The motive for the killing remains undetermined.

Horkheimer worked as a manager at the Immigration Law Project for Legal Services of Eastern Missouri and was described as gentle; he enjoyed playing the fiddle, gardening, and was planning to apply to architecture school later that month. The case went cold and remains unresolved.

If anyone knew Daniel, saw activity near his home that morning, or has information that could help, please come forward to investigators.