JOHN DiIulio has been inside more US prisons than the average criminal and spent more time with murderers, rapists and muggers than have most citizens. But there is one place that even he can no longer face.

"A few years ago, I forswore research inside juvenile lock ups," he admits. "The buzz of impulsive violence, the vacant stares and smiles, and the remorseless eyes were at once too frightening and too depressing (my God, these are children!) for me to pretend to `study' them." DiIulio nevertheless continued to study the juvenile criminals he now terms "super predators", and his conclusions are chilling. These children are the future.

In his recently published book Body Count, co authored with William Bennet and John P. Walters, DiIulio analyses the American crime scene, using hard facts and appalling case histories. The way he sees it, there is the good news, the bad news - and the even worse news.

The good news is that crime rates have recently declined in some major cities, the bad news is that youth crime rates are soaring. The even worse news is that the number of juveniles is now increasing faster than the general population and criminologists predict that the additional 500,000 boys aged between 14 and 17 years in the year 2000 will mean at least 30,000 more violent criminals on the streets. And those violent criminals will be the young people that terrify DiIulio in today's juvenile cells radically impulsive, brutal and remorseless killers.

"America is a ticking crime bomb," DiIulio warns. "And the problem is that today's bad boys are far worse than yesteryear's and tomorrow's will be far worse than today's."

Everyday horror in the US supports that prediction. Five year old Eric Morse is dropped from a 14th floor apartment in Chicago by 10 year old killers for refusing to steal candy. A 12 year old rapist returns to the school where he has committed more than a dozen assaults on six year olds. A mother waiting for her daughter to come out of Bible Study class is shot dead by three teenagers after she hands over her money, while her nine year old son sits beside her in the car. Between 1985 and 1994, juvenile arrests for murders increased 150 per cent and aggravated assault charges doubled.

"It's Lord of the Flies on a massive scale," Cook County State's attorney Jack O'Malley said after Eric Morse's murder. "We've become a nation terrorised by our children," Lynne Abraham, the district attorney of Philadelphia who has sent more mafiosi and drug bosses to jail than any of her predecessors, has "never seen anything like it . . . We're talking about elementary school youngsters who pack guns instead of lunches... We're talking big, trouble that hasn't yet begun to crest."

Even older criminals are impressed. "I was a bad ass street gladiator," a life term inmate of a New Jersey maximum security prison tells DiIulio. "But these kids are stone cold predators."

Body Count is a predictably controversial book and most of the criticism is aimed not at Bennet or Walters, who are recognisable conservatives, but at Diiulio, the maverick. A 38 year old professor at the Woodrow Wilson School of Public and International Affairs at Princeton, DiIulio looks more like a truck driver than an Ivy League academic. A Democrat who grew up in a tough, working class neighbourhood of Philadelphia, he has advised but also sharply attacked President Clinton, and bluntly dismisses both the liberal and conservative dogma on youth crime.

THE liberal argument that poverty and racism cause crime is, DiIulio insists, an insulting simplification.

"Most poor people are not criminals. They are heroes and heroines, struggling to get to work, to get their kids to school through violent streets. The rest of us don't have to drive through those neighbourhoods. We just build more integrated communities."

DiIulio agrees that the justice system is racist "in the sense that it allows the black body count to mount so high ... If we had anything like the same level of crime in Princeton that exists in Newark or Camden there would be a commitment to find out what was going on."

Instead, the growing disparity breeds complacency. Between 1985 and 1992, the rate at which males aged 14 to 17 committed murder increased by 50 per cent for whites and more than 300 per cent for blacks. Some 52 per cent of recently polled black residents said they feared for their lives on their own streets, while the corresponding figure for white anxiety was under 20 per cent.

The conservative "cut welfare" approach is equally offensive to DiIulio. "How does the sudden withdrawal of government aid lead automatically to a rebirth of civil society?" he asks. "It doesn't, not any more than pulling a knife from the chest of a dead man brings him back to life."

Body Count advances an unfashionable theory, but one that is gaining ground particularly among black community and political leaders - that the nation's current juvenile crisis is largely a result of moral poverty. This is defined as "the poverty of being without loving, capable, responsible adults who teach you right from wrong. In the extreme it is the poverty of growing up surrounded by deviant, delinquent and criminal adults."

Even critics who reject the explanation acknowledge the phenomenon. Homicide for children under the age of four reached a 40 year high in the US last year, becoming the leading cause of death for that age group. Most of those deaths were perpetrated by parents or caretakers. Some 75 per cent of violent juvenile criminals in 1995 had suffered hideous abuse by a family member and 80 per cent had witnessed killings.

Such poverty produces today's "super predator" characteristics, according to DiIulio. These children are radically present oriented, with literally no concept of the future, of deferred reward or punishment. They are exclusively self regarding, loyal only to their immediate gang. They exhibit lack of impulse control and - most critically - lack of empathy.

The ability to empathise, to sense the pain, sadness or joy of others, is thought to be essential for ethical development. There is, however, nothing intuitive about this. "Our moral sensibilities are shaped by those around us," Dilulio stresses. "We are made moral."

Princeton University demographer Professor Norman Ryder puts it more clinically. "There is a perennial invasion of barbarians who must somehow be civilised . . . for societal survival," Ryder observes, adding that the US is currently faced with a socialisation task "outside the bounds of previous experience".

JOHN DiIulio has seen too much carnage in his old Philadelphia neighbourhood to believe that the US has even begun that task. Instead he sees failed parental responsibility mirrored by failed public authority, thanks to "a false notion that the first purpose of punishment is to rehabilitate criminals, when the first purpose is moral, to exact a price for trangressing the rights of others".

Body Count praises tough law enforcement initiatives in New York City, Jacksonville, Charleston and Houston and correspondingly reduced crime rates, criticises probation laws that fill mainly poor neighbourhoods with violent repeat offenders, and argues that more juveniles be tried as adults. This hard line puts John DiIulio in the unlikely company of conservatives he vehemently criticises for cutting aid to poor children, for axing government funding of public agencies and drug treatment programmes and for opposing gun control legislation.

The tough guy Princeton professor continues to defy neat ideological classification. He is also too passionate about America's youth crisis to be satisfied with analysing it. Currently on leave from Princeton, working with Public/Private Ventures to evaluate church based social programmes, DiIulio is considering leaving academic life to work full time with black churches, the institutions in which he perceives the best hope for "children in need of adults".