Jon Richter, 45, was shot and killed at his workplace in Lennox, South Dakota, on February 12, 2015. Richter was a supervisor at Sioux Steel Company’s ProTec facility; the shooting followed a workplace dispute over a delivery assignment earlier that day.

The man identified as the shooter, 52-year-old truck driver Jeffrey DeZeeuw of Sioux Falls, returned to the office armed that afternoon, opened fire and fatally wounded Richter. Coworker Kathy Steever was also shot and critically injured. Employee Brian Roesler intervened and was hurt while trying to disarm the attacker; his actions were credited with preventing further casualties.

DeZeeuw fled but was later found dead inside a burning semi-truck near Lennox, alongside a handgun; investigators concluded he died from a self-inflicted gunshot wound and the incident was ruled a murder-suicide. Richter is remembered for his church involvement, love of music, and dedication to family and friends.

If anyone worked with Richter or witnessed events at the ProTec facility that day, what details can be added to the timeline or the people involved?