Thirty-one years ago on Sunday, an 82-year-old woman was found covered in blood and in a dazed and confused state after a burglary at her home in east Suffolk. 

On February 11, 1993, a concerned neighbour broke in through a window and found Doris Shelley cowering against her stove at her home in Martlesham. 

Mrs Shelley died 11 days later after suffering fatal injuries during the vicious attack and a murder probe was launched.

Police determined that, sometime between 2pm on Wednesday, February 10 and 12.45pm on Thursday, February 11, an unknown person or persons had broken into the property – possibly through a bedroom window.

But what actually happened during that 23-hour spell has always remained a mystery. 

Mrs Shelley's fatal injuries were inflicted 18 months after an incident which saw her house broken into.

However, it was never known if these two incidents were connected.

Because of the previous robbery, Mrs Shelley would very rarely leave the house and had a number of people run errands for her. 

Speaking on the 20th anniversary of her death in 2013, retired Suffolk police Detective Superintendent Roy Lambert told this newspaper that "examining the scene was very difficult forensically" due to the home being in a state of "disarray".

On the 25th anniversary of her death in 2018, a police appeal was issued and investigators received a "potentially interesting" tip-off.

However, a year after the possible break through, officers said nothing came of the lead and details of this information were never released to the public.

More than 70 officers were investigating Mrs Shelley’s murder at one point, and a £10,000 reward was offered to catch the killer, but even now the vital pieces of the jigsaw remain missing.

A number of people were arrested in connection with this burglary but no charges were ever brought.