Sicknick, 42, originally of New Brunswick, had bear spray discharged in his face by protestors and later collapsed after returning to his office.
He died eight hours later.
Medical Examiner Francisco J. Diaz told The Post there was no evidence that Sicknick suffered an allergic reaction to chemical irritants, and that there was no evidence of internal or external injuries.
Meanwhile, two men were charged last month with assaulting Sicknick with the spray, which some authorities believe the officer may have ingested.
Sicknick graduated from Middlesex County Vocational Technical High School in East Brunswick in 1997, according to a 1998 article in Central New Jersey Home News published in Heavy.com.
He lived in Virginia and served as an Air National Guardsman in Operation Desert Shield and Operation Enduring Freedom, his brother told the Daily Beast.
Sicknick joined the Capitol police in July 2008, where he was assigned to the First Responders Unit.
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