How police caught Mr X's killers

Det Spt Bob Varey with the reconstructed head

As two men begin life sentences for murder, BBC News Online's Chris Summers reports on the trail of clues which led police to solve the mystery of the "body in the bag" case.

The motive was an old-fashioned one - greed - but the murder of 75-year-old Mohammed Nasser Ali was only solved with the help of modern day science.

On Wednesday two men were jailed for life at Sheffield Crown Court for the murder of the short and frail retired cutler and steel worker.

The trail of clues which led to their conviction emphasises the winning combination of modern science and traditional police work.

A local man recognised the reconstructed face

The story began on the afternoon of Saturday 22 January 2000 when two men stumbled across a large sports bag dumped beside an access road on a quiet industrial estate in Attercliffe, Sheffield.

Inside, wrapped in a floral settee cover and heavy duty plastic membrane, was the badly decomposed body of a man, folded up in a foetal position.

Clues about identity

The pair immediately informed the police, who soon realised how difficult it was going to be to identify the body of Mr X.

An entomologist - an expert in the study of flies and maggots - and a botanist were brought in, in an attempt to provide clues about where the body had been stored.

A post mortem examination was carried out which deduced that the victim was between five feet four and five feet eight inches tall, had dark hair, was probably in his 50s, was of North African or Middle Eastern origin and had suffered from arthritis of the spine.

Another important clue was that he had had operations on both feet, possibly to correct bunions, but one of the screws had worked loose.

The pathologist also noted his flattened teeth, which suggested he may have routinely chewed tobacco or qat, a narcotic shrub popular with Yemenis and Somalis.

The body was found on wasteland near the city centre

Nobody matching that description had been reported missing in South Yorkshire and Detective Superintendent Bob Varey was forced to call on BBC One's Crimewatch UK programme.

First, he asked forensic anthropologist Martin Everson, from the Medico Legal Centre at Sheffield University, to reconstruct the dead man's face, using only the skull and a few wisps of remaining hair.

"Mr Everson said it was all very well reconstructing the face of prehistoric man - when it did not matter about every facial detail - but in this case it had to be very, very accurate because we wanted people to recognise him," said Supt Varey.

'I knew him'

The result was shown on Crimewatch in March last year. Although the programme did not produce any firm leads, a man from Sheffield saw the face in the local newspaper and rang in, saying it looked like an old acquaintance who he had not seen for a couple of years.

The name he gave was 75-year-old Mohammed Nasser Ali, who came to Sheffield from his native Yemen in the early 1960s.

Sheffield has a sizeable Yemeni community, the most famous member of which is world champion boxer Prince Naseem Hamed, whose image is portrayed on postage stamps in the Yemen.

Because it was so decomposed they thought we would never be able to identify it. But they were wrong.

Det Supt Bob Varey

Although Mr Ali was older than the pathologist's estimate, everything else checked out and his GP confirmed he had screws inserted in joints in both feet.

Detectives tracked down Mr Ali's son, Hassan Nasser, 43, who told them his father was alive and well and living in Saudi Arabia.

"But we were rather suspicious of him, and ultimately he was arrested, along with his own son, who was 18," said Supt Varey.

During a series of interviews the teenager, Kassan Mohammed, cracked.

'He fell on a knife'

Supt Varey told BBC News Online: "He said he had died and they had buried him in a makeshift tomb in the cellar of their home in Palmer Street, Doncaster."

Confronted with this, Nasser admitted the old man was dead but said he had "fallen on a knife" during a row about money. Police were able to prove it was no accident - his throat had been cut.

Supt Varey said: "Apparently Mr Ali had made a hefty profit - about £10,000 - from the sale of a house and was sending a lot of the money back to relatives in the Yemen, and that didn't go down well with his son."

Mr Nasser Ali...pictured on an identity card

Police believe Mr Ali was murdered in August 1998 because his son returned a Yemen Airlines plane ticket to Aden that month, saying his father had changed his mind about the trip.

The body lay in the "tomb" until October 1999 when Nasser decided to sell the house and move to Sheffield.

'Killer under-estimated police'

He dug up the body, wrapped it up, put it in the holdall and dumped it on wasteland in Sheffield.

"Because it was so decomposed they thought we would never be able to identify it. But they were wrong," said Supt Varey.

Having identified the body and the prime suspects, Supt Varey and his team set to work on getting the evidence to convict them.

Their conviction is the result of a combination of forensic science, anthropology and old fashioned police work.

Det Supt Bob Varey

They were able to prove that Nasser and his son had been claiming Mr Ali's pension, from August 1998 right up until their arrest in March 2000.

There was also evidence Nasser, an unemployed "layabout" who had only come to the UK in 1997 and was claiming political asylum, had been pilfering his father's bank account and salting the money away in the Yemen, where it was used to buy several properties.

Travelled to Yemen

Supt Varey travelled to the Yemen to visit people in the family's home village of Yafi, about two hours' drive from Aden.

His inquiries there confirmed his suspicions and in the light of the evidence Nasser and Mohammed admitted obtaining money by deception, but continued to deny murder.

But the jury saw through Nasser and Mohammed's story and found them guilty.

They are likely to spend many years in prison and Nasser will almost certainly be deported at the end of his sentence.

Supt Varey said: "Their conviction is the result of a combination of forensic science, anthropology and old fashioned police work."