£20,000 reward offered over 1995 murder of primary school teacher Joy Hewer

Police are offering a £20,000 reward for information about the killer who stabbed a primary school teacher to death in her own home 20 years ago.

Joy Hewer was sexually assaulted and left for dead in her flat in Walthamstow, north-east London, on October 17 1995.

Firefighters found the body of 52-year-old Ms Hewer in her bedroom after two fires were deliberately started in the sixth-floor flat.

Met Police has previously appealed for information about a man seen on CCTV entering St David's Court at around 10.30pm on the night of the murder.

Ms Hewer's family have made repeated appeals for help in finding her killer.

Her sister Penny Barnes said the devout Christian was "absolutely no harm to anyone" and "would go out of her way to help others".

She added: "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. She lived a quiet and peaceful life which was totally at odds with her last terrifying moments."

Detective Inspector Susan Stansfield, who is leading the investigation, will announce the reward on BBC's Crimewatch.