The Palm Beach Gardens Police Department reviewed video surveillance footage of the intersection where Williams' SUV was struck by another vehicle.
The driver, Linda Barson, was injured and her husband, Jerome, died two weeks later.
A police report initially alleged the seven-time grand slam champion was at fault for the incident, though she was not issued with any citations or traffic violations. There was also no evidence she was under the influence of drugs or alcohol, or distracted by an electronic device.