Originally from Waterford city, Jacqueline had moved with her children to a rented home at Mullinavat in Kilkenny for just a month after leaving the home she shared with her long-term partner Stephen O'Keeffe.

With her she brought to the south-Kilkenny house her eldest boy Robert, her three-year-old son Martin and her 22-month-old baby Stephen. Jacqueline and her boyfriend were struggling to cope with difficulties in their relationship but O'Keeffe and Costello remained close.

On a visit to Mullinavat, O'Keeffe noticed Costello's mental stability was deteriorating rapidly. On the morning of 28 October 2000 she agreed to accompany him to Waterford regional hospital. When they got to the facility, Costello became "quite upset".

"She was seen by a doctor and a nurse but she panicked and refused to go in and ran off, " her partner would later recount in the Central Criminal Court.

O'Keeffe was not the only one who noticed that Costello's behaviour had become deeply erratic and volatile. John and Maria Ramshaw were Jehovah's Witnesses who had befriended Costello and had remained in touch with her over that autumn.

On the 21 October the elderly couple visited her and the children at her Mullinivat home. What she told them disturbed them considerably. She insisted that she had been hearing voices. She believed that God was talking directly to her.

On the evening of 28 October the couple visited Costello and made a grim discovery. Maria Ramshaw said that she and her husband found Jacqueline Costello in the garden of the property. She was shouting and crying loudly.

When she became aware of the elderly couple's presence, she calmed slightly. She turned to them and said: "Come in then, you might as well see the evidence."

Maria Ramshaw spotted a dark form lying on the floor of the living room inside. She recounted that Costello was relatively calm at this stage and was sufficiently within her wits to advise them "not to let the three-year-old see" the scene that lay before their eyes. Jacqueline Costello then left the house and attempted to lock herself into the garage of the property.

Maria Ramshaw peered further into the living-room. What she saw shocked her. The little boy lay motionless on his back on the floor.

Sitting on his chest was a tiny kitten. "It made me feel terrible. He was lying very still, his legs spread out and his arms upf with bubbles of froth coming from his mouth, " the woman later recounted.

Maria Ramshaw could find no trace of a pulse on his body. Scattered around the room were a large quantity of tablets and bottles of 7-Up. Costello had told the couple not to drink from the bottles of the fizzy drink, as she believed them to be poisonous.

Costello would later tell gardai that she had wanted her eightyear-old son Robert to take some tablets. "I just wanted him to take the sleeping tablets. He said 'no fucking way' so I caught him by the throat and killed him, " Costello told gardai.

Pattern of instability The statement that the mother gave to gardai was illustrative of her mental trauma. In that statement she said how she had been cleaning the house on the morning of 28 October and her children were laughing at her.

"They were running around me. I had no rest at all. I just wanted to clean up and be normal, " she said.

She said that she said to Robert: "You know what has to be done, take some sleeping tablets. He said: 'I don't want them, I want to live, I want to live.'" She again told her son to take the tablets, telling the boy:

"You'll be doing us all a favour."

"I don't know what happened. I don't know where I got the strength. I put my hand around his throat, I just made sure he died. I couldn't look. I felt so sick. I just couldn't believe what happened to me." Deputy state pathologist Marie Cassidy gave evidence that Robert died primarily from asphyxiation, partial suffocation and compression of the neck as well as inhalation of gastric contents. Jacqueline had no recollection that she placed her hand over the child's mouth.

The trauma that the Costello family had endured had extended back for many years as a result of the volatile psychiatric state of their daughter. The difficulties that such a condition brought had been a considerable strain on her family. There was a clear pattern of instability in Jacqueline's history and much of the burden had fallen on the shoulders of her parents Thomas and Irene. Their daughter had tried to take her own life once in 1995 when she took an overdose of pills. On another occasion, she tried to cut herself.

In early September 2000, a visibly disturbed Jacqueline called to their home in Waterford. The parents had endured years of problems dealing with her behaviour.

They were, in the words of her father Thomas: "wrecked from it all. We couldn't go through it again, " he said. He turned his daughter away from the house. He would later describe it as his "biggest mistake".

The Costello family had endured years of suffering and had reached a threshold which they could not pass. But the eventuality of the fatal incident of 28 October was by no means inevitable.

It emerged in her April 2002 murder trial that Costello had been briefly treated with medication for schizophrenia after a suicide attempt and had responded well. However, this treatment was discontinued after a brief time. Dr Helen O'Neill, consultant psychiatrist at the central mental hospital in Dundrum, told the court that at the time of the murder, Costello believed that Robert was the "evil incarnation of her deceased brother". Dr Brian McCaffrey, an independent consultant psychiatrist, gave evidence that since the mid1990s she had been treated primarily for depression and not for schizophrenia. When counsel for the defence asked McCaffrey whether he believed that Costello should have been diagnosed as a schizophrenic he replied: "I just don't know."

Missed chances The presiding judge, Justice Butler, did not spare strong words in his comments at the conclusion of Jacqueline Costello's trial, at which the jury took just 20 minutes of deliberation to arrive at the decision that the woman was guilty but insane in relation to the murder of her child. "Poor Robert was the prime victim, but the accused [Jacqueline] too is a very real victim, " the judge said. In a statement that would parallel the circumstances of many cases where a parent had been mentally unstable and had taken the life of one or more of their children while under that mental pressure, Butler said that there had been a number of what he described as "missed chances" that could have saved the life of Robert Costello, who the judge described as a bright boy who had clearly realised the suffering that she was going through up to the final moments when her distressed state compelled Jacqueline Costello to place her hand around her eldest son's neck and prematurely end his life by force. She was sent to the central mental hospital following her conviction.

There are some clear patterns in the homicides of children in Ireland since 2000. Twenty-six young people under the age of 16 have been the victim of homicide in that period. One recurring fact remains consistent in the profile of child-homicides: more young victims are violently killed by one of their parents than at the hands of any other type of perpetrator. Sixteen of the 26 victims were killed by either their mother or their father.

Insofar as the data can be regarded as sufficient to extract patterns, there is a suggestion that mothers and fathers take their child's life in distinctly different ways. Ten of the 16 killings carried out by a parent were perpetrated by fathers. Six of the killings were carried out by the children's mother. In nearly all of the cases in which a mother took the life of her child, it was by a means that could be described as primarily non-violent. In five out of the six deaths at a mother's hand, the victim or victims were drowned. In one other case, that of young Robert Costello, the child was choked to death. But analysis shows that fathers who kill do so with considerably more force and bloodshed. While three of the 10 children killed by their father were drowned, the remaining seven deaths were considerably more brutal and bloody . . . four stabbings, one shooting and two beatings.

Extreme violence That number represents just over seven per cent of the 336 homicides that occurred in the state over the six years from the start of the decade to the end of 2005. The remarkable rise of violent crime in Ireland has ensured the country now has one of the fastest-growing homicide rates in the western world . . . up a shocking 27 per cent over the last 10 years.

In 1960 there were a total of six homicides in Ireland . . . today the annual average is almost 10 times that number. In the 1980s Ireland experienced 0.84 violent deaths per 100,000 population. This figure rose to an average of 1.1 per 100,000 throughout the 1990s, and now stands at 1.4 per 100,000.

While the population of Ireland has risen, its growth has not been as fast as our willingness to resort to extreme violence.

The rising number of Irish homicides has been fuelled by a rocketing alcohol-consumption rate. Each year dozens of young men die in drunken brawls, a situation that is worsening due to the growing knife culture amongst young people. The Irish nation's growing desire for illegal drugs has also helped to fuel the killings . . .

over 60 people were victims of socalled 'gangland' assassinations during the first six years of the decade.

But not all killings are fuelled by legal or illegal drugs. Almost one in every five homicide victims is a woman, more often than not killed by a husband or boyfriend. Of the 58 women killed in Ireland between 2000 and 2005, two thirds were killed in their homes.

What led to their deaths was not drink nor drugs . . . they were merely victims of Ireland's growing tendency to resort to extreme violence with almost no provocation.