MILWAUKEE (WTAQ) - A march is planned in Milwaukee Wednesday afternoon, where friends and relatives of Derek Williams will demand justice.

The 22-year-old Williams died over a year ago in a Milwaukee Police car, where he spent almost 8 minutes gasping for air and begging for help before he collapsed.

An early afternoon rally is scheduled at the Martin Luther King statue on Milwaukee’s north side. The group will then march to MacArthur Park near the county courthouse.

A medical examiner initially said Williams died from natural causes – but the ruling was changed to “homicide” after a newly-released video showed Williams’ final struggle.

Former judge John Franke was named Tuesday as a special prosecutor. He’ll arrange for a public inquest, in which a jury will decide whether charges should be filed.

Williams had just been taken into custody for a street robbery before his arrest and death.