[IMAGE: Victim: Joy Hewer]
Detectives investigating the murder of Joy Hewer, 20 years ago in 1995, are due to appear on BBC Crimewatch on Monday, 14 December, to further appeal for help and information.
The moments leading up to Joy's death will also be shown in a detailed reconstruction and the primary school teacher's sister, Penny, and her two nieces will take part in a heartfelt interview.
In addition to the latest appeal detectives will be discussing on Crimewatch a new £20,000 reward for information leading to the arrest and successful prosecution of the person or people responsible for Joy's death.
Officers hope the reward will encourage anyone with information about this incident to come forward and help the investigation.
Detective Inspector Susan Stansfield, of the Met's Special Casework Investigation Team, who is leading the investigation, said: "Joy was a much-loved daughter and sister and lived a quiet peaceful life.
"She must have suffered greatly at the hands of her attacker and we hope that this latest appeal, coupled with the significant police reward of £20,000, will urge anyone who can help to contact us."
Joy's sister, Penny Barnes, said: "We've waited so long for answers but we'll never give up hope. Someone has evaded us for two decades but this latest appeal with the £20,000 reward could finally help us secure justice for Joy."
Police were originally called by the London Fire Brigade at 23:45hrs on Tuesday, 17 October 1995 to reports of a blaze at a sixth floor flat.
Firefighters broke into the premises and discovered Joy's injured body in the bedroom of her E17 flat. Two smouldering fires, deliberately started in the bedroom and another in the lounge, had to be extinguished.
A post mortem examination, held at the Queen's Road Mortuary in Walthamstow, revealed the cause of death to be multiple injuries, including a number of stab wounds to the chest area.
The pathologist also indicated that Joy had been sexually assaulted prior to her death.
Joy, a devout Christian, was 52-years-old (9.5.43) at the time of her death.
She had worked locally as a much-loved primary school teacher, most notably at nearby Woodhouse Primary School. After retirement she worked relentlessly to raise money for local charities and church organisations.
Following numerous police appeals detectives were able to piece together Joy's last movements.
Officers are aware that Joy visited the London Healing Mission, in Notting Hill, on the afternoon she was murdered.
She carried out voluntary work at the Centre and was seen by a colleague leaving the Mission at around 15:30hrs. She headed towards Pembridge Road before visiting a chemist close to her home address in Wood Street, Walthamstow at 17:50hrs.
A neighbour at St. David's Court confirmed hearing loud noises or banging coming from Joy's flat at around 22:30hrs.
At 23:18hrs on 17 October 1995 a phone call was made from a public telephone box along Fulbourne Road, Walthamstow. The male caller was requesting assistance from the London Fire Brigade, having seen smoke coming from Joy's flat. Police made numerous appeals to trace this caller, previously releasing his 999 call in an effort to locate him. He is still being sought as part of the investigation as he could hold vital clues.
Whilst on the phone the caller can be heard asking someone what road they were standing in to assist the emergency call handler. He was actually speaking to someone, not known if male or female, who was standing in a queue for a bus. The bus stop would have served buses heading to Walthamstow Central (212) and to Leytonstone Station (W16). This person is yet to be located.
In addition to these two people police are also releasing a digitally enhanced CCTV still of a man they would like to trace. He was captured as he entered the front of St David's Court at around 22:30hrs.
He is white, aged between 30 to 40 years, although will now be aged between 50 and 60 years, with short hair. He was wearing a light-coloured jacket.
Although the images appear grainy, officers believe that those close to the man would still be able to recognise him.
The distraught younger sister of Joy Hewer said the thought of the attacker never being brought to justice was hard to accept.
Penny Barnes, 62 years of Bedfordshire, who is Joy's younger sister, said during previous appeals: "Joy was our loving sister who was absolutely no harm to anyone.
"She'd enjoyed her work as a teacher, adored her nieces and nephews and was fantastic with children. She regularly attended church and often helped at charity events.
"We've never forgotten the moment we were told she'd been murdered. It will never make any sense to us.
"Joy was someone who would go out of her way to help others. She lived a quiet and peaceful life which was totally at odds with her last terrifying moments.
"We need to see closure and can't face another 20 years of unanswered questions."
Detective Inspector Susan Stansfield, of the Met's Special Casework Investigation Team, who is leading the investigation, said: "Joy Hewer was a kind-hearted Christian woman who was devoted to her beliefs and to her family.
"Originally raised in Hoe Street with her younger brother Steven, and younger sister Penny, she regularly attended several churches in the Walthamstow and Notting Hill areas.
"She had worked for many years as a dedicated local primary school teacher before retiring in 1990.
"Unmarried, she continued to stay close to her family and friends and worked for various charities.
"As a result of our investigations we are sure Joy would have been cautious about letting someone enter her flat late at night. There were no signs of a forced entry and it may be that she knew the person who entered her flat that night. Our forensic teams also found two used coffee cups within the address.
"After two decades we realise a lot of time has passed and someone who may have not spoken out in 1995 may feel they can come forward now, 20 years on.
"We hope that this latest appeal will enable someone with the final piece to the jigsaw to speak out.
"Anyone with any information is asked to contact our Incident Room on 020 7230 7963; alternatively, to remain anonymous, call Crimestoopers on 0800 555 111."
The BBC Crimewatch appeal is due to broadcast on BBC1 at 21:00 on Monday, 14th December.