On 29 December 1982, Jeffrey May was found on the concrete floor below the tramway bridge over the Sturt Creek at Glengowrie.
Investigations revealed that the 19-year old and his friends were set upon by a group of persons and Jeffrey was assaulted on the tramway bridge while trying to escape.
As a result of the assault he fell to the concrete creek bed below and sustained critical injuries.
Jeffery left behind a partner and a young daughter, with another daughter born whilst he was on life support fighting for his life.
A reward of up to $200,000 remains on offer to anyone who provides information leading to a conviction in the case.
Anyone with information is asked to contact Crime Stoppers on 1800 333 000 or at www.crimestopperssa.com.au