THEY are the murders that have baffled gardaí and left grieving families searching for answers. Since 1980, there have been 207 unsolved murders in Ireland. The Serious Crime Review Team, commonly known as the cold-case unit, was set up in 2007 to take a fresh look at unsolved murders. For the families of those left behind, it offers reassurance that the killing of their loved ones remains a garda priority. It also offers hope for grieving relatives. This is something gardaí are keenly aware of and efforts are made to ensure families' expectations are not raised unduly, only to be dashed. From an investigation point of view, the unit provides an opportunity for 'fresh eyes' to re-evaluate all the evidence objectively in each murder and try to progress the case. Officially, gardaí have released the names of less than a dozen murder cases they are probing. But in reality, the cold-case team is currently involved in reviewing 70 unsolved murders across Ireland.

Various modern investigative techniques such as forensic advances, DNA and changes in how evidence is handled mean that cases that have been 'cold' for years can see major progress today once the original case is reviewed.

The cold-case unit is led by Detective Superintendent Christy Mangan. The team is located at the National Bureau of Criminal Investigation (NBCI) at Harcourt Square, Dublin. The unit had its first major success in July, when a 61-year-old woman was sentenced to life in prison after being found guilty of murdering her husband at their Westmeath home 23 years ago. Vera McGrath had pleaded not guilty to murdering her husband Brian McGrath in 1987. She admitted hitting him once during the killing and being involved in the burial, digging up, burning, chopping up and reburial of his body. Her former son-in-law, Colin Pinder, was found guilty of McGrath's manslaughter but cleared of his murder. Pinder, from Liverpool in England, had admitted killing his fiancée's father but denied murder.

The decision to establish the cold-case unit was made after the success of such operations in police forces worldwide.

It is understood several other cases the unit is now investigating have made considerable progress and officers are optimistic about solving other murders.

Antoinette Smith

The 27-year-old disappeared from Dublin's Westmoreland Street in July 1987 after attending a David Bowie concert at Slane Castle in Co Meath. Her body was found in the Dublin mountains nine months later. She had been raped and later suffocated with a plastic bag.

Following the concert, the mother-of-two had returned to Dublin, and the Harp Bar at O'Connell Bridge, before going on to a disco on Parnell Street. Her disappearance was reported to gardaí. It was treated as a missing person's case until her body was discovered, and any forensic evidence had been lost at this stage.

Niall Hanlon

The 22-year-old was murdered in 2001, and was officially missing for six months before his remains were discovered in the grounds of St Kevin's College, Sundrive Road, in south Dublin.

Hanlon was found to have multiple stab wounds and his body had been severely mutilated. One suspect in the murder is a well-known Dublin drug dealer who had been jailed previously for armed robbery.

Hanlon was stabbed more than 30 times. His death is believed to be linked to a failed attempt to steal over €300,000 from the drug dealer.

Raonaid Murray

The 17-year-old was stabbed to death close to her home in Glenageary in south Dublin in 1999. It is one of the most high-profile unsolved murders in Ireland. The original garda probe was extensive – more than 8,000 statements were taken and 3,000 people were interviewed.

The cold-case investigation began two years ago. Because of the sheer volume of statements taken, its review is still ongoing. It is understood detectives are anxious to speak to three women, acquaintances of Raonaid, who no longer live in Ireland.

Eddie Fitzmaurice

The pensioner was found dead at his home in Bellaghy, Charles­town, Co Mayo, in May 1998. The 83-year-old businessman, who lived in rooms above his drapery shop at Bellaghy, was left to die in his bedroom after he had been assaulted, gagged and bound to a chair.

His remains were not found until five days after the horrific incident and this delay hampered the garda investigation from the outset.

Dessie Fox

In 1990, the 47-year-old was en route from his home in Dungannon, Co Tyrone, to a race meeting at the Curragh when his car was intercepted by a number of men. He died from a single gunshot wound.

A bookmaker by trade, he was in possession of a sizable amount of cash when he was ambushed. The money was stolen. Earlier this month, Dessie Fox's family made an appeal on RTÉ's Crime Call.

Emer O'Loughlin

The body of the 23-year-old art student was discovered in a burnt-out caravan in Co Clare in April 2005. Her body was exhumed last year and a second post mortem, due to advances in forensic science, confirmed that she was murdered. Until now, the cause of death had not been known but it was treated by gardaí as suspicious.

O'Loughlin was living with her long-term boyfriend Shane Bowe at a caravan park at Newline, Ballybornagh, between Kinvara and Tubber in Co Clare, at the time of her death.

After O'Loughlin was murdered, her caravan was set on fire.

Days after her murder, a neighbour of O'Loughlin's who was in his 30s attempted to fake his own suicide and has now left the country. Gardaí say he is key to their enquiries and his details have been circulated with Interpol and Europol.

Christopher Payne

The 52-year-old from Crumlin, Dublin, was left "like a vegetable" after being attacked in his home. Payne suffered from a chronic kidney ailment and died six months after the assault. Two men were jailed for their role in the 1988 attack but said the dead man's wife and daughter offered them £3,000 to murder him.

Philomena Payne and her daughter were arrested in connection with the attack on Christopher Payne shortly after his death but were not charged. Detectives are trying to establish the whereabouts of the two women.

No pathologist could definitively say his death was directly linked to the beating.

Grace Livingstone

The 56-year-old mother-of-two was found face down on her bed in her Malahide, Dublin, home 17 years ago by her husband. Her feet and hands had been bound and her mouth was gagged with adhesive tape.

She had been shot in the back of the head. There was no sign of a burglary and no apparent motive was uncovered.

A garda review of the original investigation a few years ago came to the conclusion that Grace Livingstone had been killed about an hour before her husband James, a tax inspector, arrived home and found her body in their bedroom.