Phil Coulter spoke for many when he said last Tuesday that this wasn't happening 20 years ago. The musician was speaking on RTé's Liveline about the tragic events in Bray in which Sebastian Creane and Shane Clancy lost their lives. Coulter's son had been a close friend of Seb Creane. The notion that this type of crime and tragedy is a recent phenomenon is wide of the mark, but his perception is a common one among the general public.

This kind of thing did happen 20 years ago. In 1988, John Gallagher shot to death his ex-girlfriend Annie Gillespie and her mother Anne in the grounds of Sligo General Hospital. Gallagher was subsequently found to be guilty of murder but insane. A spurned or jealous man intent on killing his ex-girlfriend/ partner/ wife is not new. Neither is a compulsion to kill any new boyfriend on the scene.

The waste of human life that occurred last Sunday morning in Bray is heart rending. The lives of the families concerned have been shattered. But unfortunately, the incident isn't unique.

One aspect that separates the incident from others of its kind in the past was the method of murder and suicide. Clancy bought the knives in a premeditated fashion once he had determined how he was going to act. Extreme violence is required to stab somebody to death, more so than, for instance, shooting, or even perhaps strangulation. To then commit suicide using the same method suggests a desensitisation to extreme violence that is difficult to comprehend.

A raft of stabbing incidents in Co Mayo in recent days have left one man dead and four injured, heightening fears of random violence. In one of the incidents, Garda Daryl Mullen was stabbed. A 16-year-old youth has been charged in connection with that case. Elsewhere, the body of Romanian woman, 50-year-old Eugenia Bratis, was identified 10 days after she was found stabbed to death in the Phoenix Park.

Once again questions are being raised about violence, and particularly the violence associated with young people and knives.

Ireland is certainly a more violent country. In 1989, 16 murders, two attempted murders and five manslaughters were recorded. In 2008, there were 50 murders and five manslaughter offences recorded. The latest statistics for the first quarter of this year show a 35% drop in homicide figures.

On the face of it, this implies a much more violent society. Eighteen of the 50 murders last year were gun killings, linked to gang crime. Yet, by international standards Ireland's serious crime rate remains low. Twenty years ago, the country was a backwater, with no immigration and certainly no market for lucrative drugs like cocaine. The development of the country, through what was a credit-fuelled bubble economy, was inevitably going to bring a rise in serious and violent crime.

John Lonergan, the governor of Mountjoy prison, believes the viciousness associated with violence has increased in recent years. His experience as governor of a prison through which most committals for serious crime are processed, and in which violence is an everyday threat for inmates, informs his insight. "In the last five-year period there has been a massive increase in savage violence," Lonergan says. "My personal view is drugs are at the core of it, and drink to a lesser extent."

He has noticed the increased use of knives, particularly in relation to serious assaults and homicide, but says it is the underlying conditions that need to be examined. "Young people are conditioned by the culture around them, but I also think that if a human being is inflicting injury on another human being, or even an animal, there must be some inhibiting feelings. These days it is done in such a vicious way, and there doesn't seem to be any real remorse. We need to look at that."

The recent incidents have focused on knife crime, which is a growing phenomenon. Last year's homicide total of 55 included 15 through stabbings, although this was down from 37 the previous year. A total of 1,030 incidents of knife crime have been recorded this year so far.

Tim Trimble lectures in psychology in TCD and has been working with young offenders for over 20 years. He cautions against over-reacting to a cluster of incidents, but has seen changes in the people he deals with. "When I started out a lot of the crime being committed by young offenders was non-violent. That has changed," he says. "In popular culture you have the media, with games and TV programmes where a lot of the role-model characteristics are aggressive. There is also the issue of family instability. Those most likely to come to the attention of the authorities would have had an early history of family instability."

Trimble also sees the emergence of a gang subculture among adolescents in some disadvantaged areas that acts as a substitute of sorts for family. In doing so, they acquire what he refers to as a "micro-ethnic identity".

As with all matters criminal, there is a socio-economic aspect to this phenomenon. "The more affluent young people are likely to have protective factors in their lives and are less exposed."

The answers to tackling these kinds of problems are as old as the hills, but still not recognised with sufficient resources at official level. "If the support structures are put in place, it does make a difference," says Trimble.

Tony Bates is the founding director of Headstrong, an agency for youth mental health. He cites drink, drugs and the media as being determinants in young people's attitudes to violence.

"They are exposed to images that implicitly give permission to commit violence. The horror of it doesn't quite hit them. But the way they behave reflects the ethos of the society they live in."

He points out that surveys show that large numbers of teenagers begin binge drinking by the age of 15 or 16. "It is a big problem with young people," he says.

"The real question for young people is what is their experience when they get upset. What would help, what doesn't help." But he cautions against reading too much into isolated incidents. "There are episodes of violence that have very little to do with societal or cultural factors, but personal factors instead. These can't really be accounted for. On one level, if we get into that kind of thinking, nobody has any responsibility."