Blood and gore is not perhaps the tone generally attributed to Picoult's previous books. Though Nineteen Minutes is very much written in the same style as its predecessors, focusing intently on the relationship between parents and adolescents, it is Picoult's most graphic and gripping book so far.

The story centres on the perpetrator of this unthinkable but precedented tragedy, Peter Houghton, and his ex-childhood friend, Josie Cormier.

Cormier is the 17-year-old daughter of a judge. Judge Alex Cormier and local midwife Lacy Houghton struck up a close friendship when the judge was still a defence attorney who had conceived a child with a married man. Lacy's son, Peter, and Josie always played together until the two mothers fell out over the discovery of the children playing with Peter's father's hunting rifle.

Although they no longer went over to each other's house they remained friends at school, even though it was evident from the very start of school that gentle and sensitive Peter was being bullied.

When they reached their teens Josie, who had also never felt very comfortable in her own skin but hid it better, broke away from her friend in order to be popular and go out with Matt Royston, the school uber-jock and one of Peter's chief tormentors.

Josie's father wanted nothing to do with her from the start and her mother, though primevally protective of her daughter, is too busy with her career and public image to realise how distant their relationship has become. However, it is the son of the seemingly ordinary, nuclear, family . . . his mother a midwife, a giver of life; his father a specialist in the economics of happiness . . .

who becomes a rampaging murderer.

Beginning with the high-school shootout, Nineteen Minutes doesn't let up for a moment, not in its questioning of what drives a 17-year-old to kill indiscriminately;

not in its analysis of family life versus family ideals; not in its treatment of the straitjacket of teenage hierarchies; and certainly not in terms of holding constant dramatic tension.

Although the chronology jumps between the build-up to the shooting and the court trial afterwards, Picoult has managed to pull it off seamlessly. Her less conventional style (in previous novels she has used comic bookstyle illustrations) has led her in this instance to use short excerpts of thought from Peter to punctuate the story and explain his mentality to the reader.

Whilst everything with Peter seems to be painfully out on the surface, Josie is keeping herself and her mind well hidden.

Questions arise as quickly as they are dealt with. Can Alex and Josie form a close bond again? What does Josie really remember about the shooting she survived but her boyfriend didn't? Was Lacy a bad mother, did she do the wrong things at important moments in Peter's young life?

What effect, if any, did his father's hunting hobby have on Peter's decision to shoot up his schoolmates?

It's these questions and the countless other ones thrown up in the book that make Picoult the perfect fodder for book clubs.

Some of her paperbacks have contained book club questions in the back for interested groups to discuss.

Although highly readable, her novels are not cliched or simple. The more intricate the moral dilemma, the more she seems to like it. How sorry should we feel for Peter, the boy who got his lunch box thrown out the bus window on his first day at school? Can anything ever justify the murder and injury he inflicted on others? In the longer term what difference have his actions made in the bigger scheme of things? Was Josie the worst perpetrator of cruelty on Peter for allowing her friends to beat and humiliate him when she had been his friend? How tight knit are these so-called popular groups of friends who hang out with each other day and night?

The questions are as endless as they are thought provoking. Yet the ending is an apt conclusion to a deeply satisfying read.

Picoult packs in more moral dilemmas than 10 years' back copies of a teenage problem page. What she seems truly fascinated with is that odd twilight world between childhood and teenage years.

Perhaps because they are so difficult to decipher, teenagers are generally a quiet demographic but Picoult manages to delve into their worlds and their heads without becoming morose or judgemental.

One thing is for sure, though, if you have children, Picoult manages to burrow into the parent/child dynamic and psyches like no one else and it's scary in there.

What's more scary is when it results in the type of destruction witnessed only this month once again in an American school.