Detectives are urging people to take another look at CCTV images taken in the park where James Attfield was found murdered.
Many have already been identified - one in just a few minutes after a Twitter appeal.
There are eight images outstanding and detectives are hoping they may hold vital information that could help with their inquiries.
The people in the CCTV may have seen something that could help the murder investigation team.
The outstanding images are below.