Police across the United States are on high alert. They're bracing for more unrest, following a pattern of peaceful protests descending into violence.

Tens of thousands of people are marching against social inequality -- sparked by the death of a black man in police custody one week ago.

Results of an independent family autopsy show George Floyd died from 'asphyxiation from sustained pressure'. 

Floyd's brother has been to Minneapolis to pay tribute at his brother's memorial. 

CGTN's Dan Williams reports.