According to evidence tendered in court, Loveridge had attacked four other young men on the night he killed Thomas, splitting the eyebrow of one with an elbow to the head.

After so many other deadly one-punch attacks in the past two years - including that on Daniel Christie on New Year's Eve – the debate has been re-ignited about seemingly callous assaults on strangers, attacks that are nearly always fuelled by alcohol.

State MP for Baulkham Hills David Elliott (Thomas attended school in that area) said Loveridge's actions were the "very definition of evil".

"Evil is flourishing and it is time the judiciary of our state began honouring their commitment to justice and human rights for all - not just those who come before the bench," Elliott told Parliament after the sentencing.

The words "wickedness" and "evil" have gained popularity in recent years, especially since the terrorist attacks in New York on September 11, 2001. But the meaning of the words is not clear, says Senior Law Lecturer at the University of Technology, Sydney (UTS), Dr Penny Crofts.

"The media, community and political response to the very sad death of Thomas Kelly can be regarded as a social debate about what it means to be wicked, and the role of the criminal law in constructing notions of right and wrong," says Dr Crofts.

"Criminal law organises wickedness whether it wants to or not and we should critically evaluate the models of wickedness that are expressed in the law."

Despite the importance of wickedness in criminal law, the question of what it means to be wicked is either avoided or ignored.

In her new book Wickedness and Crime: Laws of Homicide and Malice, Dr Crofts seeks to expose the ways in which criminal law communicates and sanctions different types of wickedness in contemporary society.

In criminal law, the dominant account of wickedness is that of subjective blameworthiness, she says. A person cannot be guilty unless they did the wrong thing intentionally or knowingly.

"This is a very thin account of wickedness," says Dr Crofts. "It doesn't account for all the different ways of being wicked or what the criminal justice system actually does."

If a person intentionally kills someone they may not be guilty of murder if they didn't want to kill them - if they were forced by a threat to murder. "This is an emotional account of wickedness that moves beyond a focus on intention," says Dr Crofts.

Dr Crofts has found that in older philosophical and legal models, wickedness is related to an absence of goodness and a failure to care.

"We need an account of wickedness that includes an evaluation of individual emotions and thoughts as well as external or objective evaluation of what their actions were threatening," says Dr Crofts.

Just because a person did not want to kill someone does not mean they should not be held responsible.

"If a person failed to exercise care for a value [life] that we as a society enshrine as important, they could be regarded as wicked," says Dr Crofts.

For more Brink stories go to http://newsroom.uts.edu.au/brink

This story written and produced by the University of Technology, Sydney, for Brink, a publication distributed monthly in The Sydney Morning Herald