Iowa crowd control expert witnesses assess planning, staffing, and use-of-force practices for managing large gatherings. Many are former law enforcement commanders, security directors, or event-operations professionals with training in de-escalation, barrier design, and incident command. In Iowa, their work often reflects crowd-management needs at Hawkeye football weekends and the Iowa State Fair. They evaluate adequacy of policies, training, communications, and response to surges, fights, or stampede risks.