Police investigating the murders of two 11-year-old boys 40 years ago are trying to trace potential witnesses who could have vital information.
School friends John Greenwood and Gary Miller were found hidden under a mattress in a rubbish tip in Whiston, near Liverpool, by a dog walker in the early evening of Saturday 16 August, 1980.
The boys were taken to hospital from the scene in Pottery Lane, in an area now known as Stadt Moers Park, but died from head injuries.
A man named John Cheeseman, from Prescot, went on trial in 1981 for their murders but was found not guilty.
Merseyside Police, who reopened the probe in 2016, said they have spoken to a number of people but want to trace potential witnesses who they believe could have vital information to the investigation.
More specifically, they are looking to trace two boys who are said to have been assaulted by an older man outside Whiston Health Centre in July 1980. It is believed the boys were aged between 10 and 15 at the time of the attack.
Detectives also want to track down a boy called either "Duffy" or "Cuffy", who was also aged around 10 to 15, who was in the company of another boy at the Labour Club in Whiston on the day John and Gary were found.
More from Liverpool
Anyone who attended the 28th St Helens Scout Group in 1980 or went to Halsnead junior school around the same time as John and Gary is also being asked to come forward.
Speaking on behalf of both families, John Greenwood's sister, Debbie Lewis, said: "Our families' hearts were broken 40 years ago when two loved and cherished boys were taken.
"Forty years later those broken hearts have not healed. I see the pain in my parents' faces. They live with loss and injustice.
"I appeal to our community today, please, it's not too late to do the right thing. You could make the difference. You could help to bring some peace to these broken people."