Capitol Officer Brian Sicknick died of natural causes after defending Capitol, ME says Published: April 20, 2021 7:57 AM EDT Updated: April 20, 2021 10:18 AM EDT Recommended Capitol Police Officer Brian Sicknick died of natural causes a day after defending the Capitol during the January 6 assault, the D.C. medical examiner’s office announced Monday. Sicknick was previously believed to have died from injuries sustained during the riot. Sicknick died from strokes, the chief medical examiner’s office said in a report summary, citing “acute brainstem and cerebellar infarcts due to acute basilar artery thrombosis.” In an interview with The Washington Post, chief medical examiner Francisco J. Diaz said Sicknick suffered two strokes at the base of his brainstem caused by a clot in an artery.