Lynne Weedon, 16, was raped and beaten to death near her home in Hounslow, west London, in 1975.
Her case remains unsolved but has been linked to the killing of Eve Stratford six months earlier.
Lynne was on her way home after an evening out with friends and was attacked after entering an alleyway called The Short Hedges of the Great Western Road at around 11pm on 3 September.
She was hit with a blunt instrument and thrown over a fence into the grounds of an electricity substation. She was then raped.
Lynne was still alive when she was found by a local school caretaker whose house overlooked the sub-station. She never regained consciousness and died a week later in hospital on 10 September 1975.
The cause of death was a single blow to the head which caused a skull fracture. The weapon was never recovered.
In 2004 officers from the Metropolitan Police’s Murder Review Group re-examined Lynne’s case and recovered a DNA profile. Further checks revealed a match to a DNA profile linked to Eve’s murder.
A £40,000 reward is on offer for information leading to the conviction of those responsible.
On the 40th anniversary of the murder, investigating officer Detective Chief Inspector Noel McHugh, from the Homicide and Major Crime Command, made a direct appeal for the killer to come forward.
He said: “I firmly believe there is someone out there who has information about who carried out these murders. It is inconceivable the killer of Eve and Lynne has kept the perfect secret for 40 years. It’s a heavy burden to carry and he must have let details slip over the years – maybe to a partner, a friend, even a cellmate – and I would appeal to anyone with information to contact us. The families of Eve and Lynne had spent decades not knowing who brutally killed their loved ones and they surely deserve some answers.
“The man who carried out these murders is now of a different, older generation. I would imagine he must have reflected upon his actions every day over the past 40 years.
“Does he feel guilt, remorse, a need to explain what happened? Sadly Eve’s parents have passed away but this man has a chance to bring peace to Lynne’s mother and father, now in their 80s.
“I am directly appealing to that person to come forward and speak to us and make things right for the sake of the families affected.
“One phone call to the incident room could be all that it takes to bring two bereaved families closer to some closure or justice.
“I urge you to examine your conscience and if you are wavering on making that call, think of Eve’s family who have now passed away and Lynne’s parents who are in their 80s and have endured 40 dreadful years not knowing who murdered their daughter. Perhaps the person who killed Lynne and Eve confided in you? Please do not keep their secret for a day longer and come forward.”
Anyone with information is asked to call the incident room on 020 8785 8099 or Crimestoppers anonymously on 0800 555 111.
1975 seems so long ago and it is. We have missed out on so much; she missed out on life, no relationship or marriage, no career or children or even just travelling the world, all taken from her. We are left wondering what it would have been like. A true life sentence.
We are well aware that whoever murdered Lynne also murdered Eve Stratford. That young lady also had her life snubbed out. Her family have died now. Another true life sentence. The hurt eases but the pain still sits deep somewhere inside. There are so many questions. So many thoughts. So much heartache.
I will make a mother’s plea for anyone who can tell us some information about the person who took my daughter and Eve Stratford’s lives to come forward. Please, please give us some sort of closure.Lynne’s mother Margaret Weedon, speaking in March 2015
This case is featured on the historical murder map of London.