A lot of murders are solved promptly but some cases continue to haunt the public for years to come.

There are nearly 1,600 unsolved murders in Britain, and here are four that happened in the News Shopper area.

Louisa Smith, February 1889

Prostitute Louisa Smith was found in Algernon Road, Lewisham, with a severe fractured skull caused by a blow with a blunt instrument.

Her killer was never found.

Debbie Lindsley, March 1988, train from Orpington to London Victoria

The murder of a 26-year-old Bromley woman on a train is still baffling investigators almost 30 years later.

Debbie Linsley boarded the 2.16pm Orpington to Victoria train on March 23, 1988, at Petts Wood station, and entered an old fashioned compartment with room for six people and doors at each side of the carriage.

Somewhere on the journey between Petts Wood and Victoria, the senior hotel receptionist was stabbed at least five times.

The train arrived at platform two at Victoria Station and at around 2.50pm, when British Rail staff were checking for any passengers, Miss Linsley’s body was discovered on the floor surrounded by blood.

A post-mortem examination gave the cause of death as a stab wound to the heart.

Daniel Morgan, March 1987, Sydenham

This Is Local London: Daniel Morgan was murdered on March 10, 1987

Private investigator Daniel Morgan was 37 years old when he was found with an axe in his head in the Golden Lion pub car park on March 10 1987.

An independent panel was set up by then Home Secretary Theresa May in May 2013 after numerous inquiries at a cost of around £30 million failed to shed light on Mr Morgan's murder.

Scotland Yard has admitted that corruption was a ''debilitating factor'' in the first investigation.

Sam Guidera, February 2011, near Penge East Station

On Saturday, February 12 2011, Sam Guidera was found collapsed in the street in Bailey Place, at the junction with Newlands Park, about 200 metres from Penge East station.

Mr Guidera was stabbed in the heart. His wallet containing a Greenwich University student card was stolen from him and has never been found.

On the night of his death he had travelled on the 9.17pm train from Bickley to Penge East, arriving just after 9.30pm.

He crossed the footbridge over the railway to the Newlands Park exit as he was on his way to meet his girlfriend.

The 24-year-old was last seen, before being found stabbed, at a bus stop opposite Bailey Place shortly before 9.40pm.

His mother and father, Sarah and Chris Guidera, in a statement released in February this year said: “We just want somebody out there who knows something that could help in the apprehending of the killers to come forward so they do not have the opportunity to take another person's life and destroy another family.

“It could be somebody reading this who gets the call about the savage death of a loved one next.”