WASHINGTON (AP) – The Washington, D.C., medical examiner’s office says Capitol Police Officer Brian Sicknick suffered a stroke after confronting rioters on Jan. 6 and died of natural causes. Investigators initially believed the officer was hit in the head with a fire extinguisher, based on statements collected early in the investigation. They later thought Sicknick may have ingested a chemical substance – possibly bear spray – that may have contributed to his death. But the determination of a natural cause of death means the medical examiner found that a medical condition alone caused his death. The determination is likely to significantly inhibit the ability of federal prosecutors to bring homicide charges in Sicknick’s death.