A medical examiner's office on Monday ruled that the death of George Floyd, the black man whose killing in Minneapolis police custody last week triggered nationwide protests, was a homicide and that he died from asphyxiation.

The medical examiner's finding that the death was a homicide confirms the same conclusion of the independent autopsy that was also released on Monday, but there are key differences over the cause.

A press release from the Hennepin County Medical Examiner said that Floyd, who struggled to breathe as an officer pinned him down by kneeling on his neck, had "recent methamphetamine use" and "fentanyl intoxication" — along with hypertension and coronary artery disease — all of which were possible contributing factors to his death.