One of the most disturbing cases ever to be heard by an Irish court came to a conclusion last week when a Dublin teenager called David Curran was given a life sentence for the brutal murder of two Polish men.

The two Poles, Pawel Kalite, 30, and Marius Szwajkos, 29, were both stabbed in the head with a screwdriver by Curran two years ago when he was 17. Despite the fact that Curran (pictured above, right) was just a kid, he was so hyped up on drink and drugs at the time that he was able to kill both men in a few seconds.

The ferocity of the attack was truly shocking and has led many people here to wonder how Irish society can produce a twisted, vicious youngster capable of such barbarism.

It happened in February 2008, in the Drimnagh area of Dublin, one of the old blue collar parts of the city where there are some trouble spots, but nothing like the real problem areas in the desolate new suburbs to the north and west of the city.

The two Polish men, both mechanics, were living in a rented house in the area and working in a small local garage. Their employer said that they were quiet, decent men who were good workers.

It was while on the way back to the house after a hard day's work (even though it was a Saturday) that Kalite called into a takeaway to get a bag of chips. He was coming out of the chip shop when a young teenage boy from a group of teenagers bumped into him, probably deliberately.

Kalite was angry, began to chase the boy around and there was a scuffle with the teenagers. A man who was passing by became involved. Kalite was knocked to the ground in the scuffle, during which time he was punched and slapped by the teenagers, two of whom were teenage girls.

He picked himself and his bag of chips up and made it back to the house, which he shared with several other Polish people who were also working in Dublin. One of his housemates said she could see how upset and humiliated he was at being beaten up by a gang of teenagers, some of whom had now arrived on the street outside the house. She and another Polish man begged Kalite not to go outside again.

But he did, and within seconds he and his friend Szwajkos, who had gone out to help him, had both been stabbed through the temple with a screwdriver wielded by Curran. As both men lay dying on the ground with blood pumping out of their heads they were kicked repeatedly in the face.

Looking at Curran last week, it was hard to believe that he could be capable of such deadly viciousness. He has what used to be called a typically Irish face, pale skin with freckles under a head of red hair. He looks like an average, skinny Irish teenager, and the pale complexion and freckles give him a look of childish innocence.

But behind this facade is something which the judge in the case last week called "profoundly sinister." Passing two life sentences on Curran, the judge said that with "lethal accuracy" he had aimed at the most vulnerable part of the human body -- the temple.

He added that Curran's actions left "a chilling and disturbing feeling as to what kind of a person would do this." The killings, he said, were "brutal, savage and could be described as sadistic."

It was this aspect of the murders that was so disturbing to people here. To be able to swing a fist holding a screwdriver with enough precision and force to penetrate through someone's temple and deep into the brain requires a combination of aggression, sadistic intent and accuracy.

It's not something that would be easy to do, or possible to do by accident. Yet this 17-year-old teenager was able to do it with deadly accuracy and effectiveness not once, but twice, in the space of a few seconds.

What can be the mentality of a teenager like that be? What can the family background in Dublin be that produces such a teenager?

What emerged in court was a picture not just of Curran as an individual but of the group of teenagers he was part of, an out of control, almost feral bunch of kids. These aimless, feckless, moronic youngsters were illogical and highly aggressive, with no sense of restraint.

With nothing meaningful in their lives, minor events (like bumping into someone) assumed massive proportions for them and were transformed into imaginary major insults.

When stoked up on drink and drugs they were capable of appalling violence, almost on a whim. And there were girls involved as well as boys.

Almost as disturbing as the violence was the behavior of this group in the hours before the murders. They had spent that Saturday on waste ground near the canal in Drimnagh, drinking heavily, smoking cannabis and taking pills.

It was a cold February day but some of them went swimming, so high they were insulated from the chilling canal water. There was nothing unusual in this. It was just another day down at the canal, Curran told the court.

He had been thrown out of school at 15 and had behavioral and drug problems which a counselor had been trying to deal with. Although he lived at home, he spent most of his time robbing to fund his drinking and drug taking.

With Curran that day was Sean Keogh, a friend of his who was two years older, and some younger teenagers including two girls. They were drinking vodka and alcopops, and taking drugs. The session went on all day, moving from the canal bank to a nearby field.

At some point the group split up, with Curran and Keogh heading off to find somewhere to rob and the younger ones heading for the local chip shop.

This is when the incident with Kalite happened. The man who had jumped out of a passing car and intervened in the scuffle was David Curran's father, and the boy Kalite was chasing around was his nephew.

The man grabbed Kalite by the throat and pushed him up against the shutters of the butcher's shop beside the takeaway. Kalite was punched, collapsed on the ground and was kicked.

The butcher came out to try to calm the situation, and Kalite got up and headed for his house further up the road. On the way, one of the teenage girls who had attacked him threw a bottle at him and screamed racist remarks.

In the meantime, Curran and Keogh had stolen a motorbike and found a pointed Phillips screwdriver when Curran got a call on his cell from one of the girls who was upset and wanted him to come and help deal with the Poles.

He claimed later in court that he had been told that his father had been stabbed but the court did not believe this. Arriving at the chip shop he was in a highly aggressive state, and went with the group of teenagers up the road looking for Kalite.

All the time he was being egged on by the girls. When they got to the house, there were teenagers outside and the two Polish men and a woman were standing in the small front yard.

Curran went for them, the woman ducked out of the way and seconds later the screwdriver had been driven into the brains of the two Polish men. Keogh kicked them in the head when they were on the ground.

Curran realized they were dead and ran away. He told the court he went home, had a curry for dinner and then threw up.

And all that night and the next day he and one of the girls who had been involved sent text messages to each other about what had happened.

One of the messages the girl sent said: "Ha ha, like I can't believe it. Mad nite xxxx."

For the jury in the case and people generally, these messages were shocking, revealing how callous and alienated these kids were.

The victim impact statement from the relatives of the murdered Polish men was heartbreaking, showing what decent, quiet, non-violent people they were, working hard to make a life for themselves. The contrast with the vicious, mindless young Irish teenagers who had attacked them was striking.

The case has left an aftershock of concern here. People know only too well that in post-boom Ireland there are a lot of violent, feckless youngsters whose only aim seems to be to get the maximum amount of drink and drugs into themselves.

They have no vision, no ambition. Instead of hope they are filled with resentment and are ready to turn to extreme violence if someone even looks at them the wrong way. Especially an immigrant.

The cause of this situation includes dysfunctional families where the parents are almost as bad, and inadequate schools which spend hours teaching Irish but fail completely to instill a sense of responsibility and citizenship in the kids, or even an ability to read and write.

There's always been a problem of this kind here, of course, and it's not unique to Ireland. But what's new now is the immediate resort to extreme violence, even murder, as a first response.

That is what is illustrated by this case and it's very scary.