KEY POINTS:
They are mostly white men in their 20s. They usually come from poorer, large families and broken homes, often with a long criminal history, poor social skills and are unemployed or working in unskilled jobs.
This is the profile of an arsonist, though it's a best-shot list of characteristics because so few are caught the data is limited.
The outline comes from international research and is contained in a new study from the Australian Institute of Criminology. Australia has more than its share of arsonists: of the 60,000 bushfires the nation records each year, as many as half - 30,000 - are deliberately lit or suspicious. Arson costs the nation A$1.6 billion, making it the fourth most expensive crime category after fraud, drug offences and burglary.
Few arsonists are caught.
"The ease of lighting a fire and the difficulty of linking a particular fire to a particular individual, particularly to the extent that it satisfies the burden of proof of a criminal court, means that few arsonists are successfully prosecuted," the study said.
One of the handful actually convicted was Peter Cameron Burgess.
Aged 20, unemployed, bored and impressed by the New York firemen at the World Trade Centre in the September 11, 2001 attacks, Burgess began lighting fires across NSW. He joined local volunteer fire brigades, called in alarms, and helped fight the fires he had lit.
By the time he was finally caught and jailed for two years, Burgess had set more than 20 fires.
Last year he consented to an interview with the Nine Network's 60 Minutes programme, providing a rare and chilling insight into the mind of a man prepared to risk lives, homes and property.
"I never actually thought about the general public," Burgess told interviewer Liam Bartlett. "I didn't think about anything."
He knew what he was doing, and accepted that his kicks could have led to murder. "I couldn't get work so I felt useless, you know. The only thing that would make me feel useful was to go out and light a fire...
"There was definitely something, some sort of excitement there. There was definitely the thrill.
"There was a lot more adrenaline - get on the back of the truck with the boys ... and fly off to the fire and try to knock it out as quick as possible."
Other rogue firefighters have taken their toll, although they are few in number. A NSW police strikeforce set up to investigate the causes of 1600 suspicious bushfires in three years charged 50 people, 11 of them members of the state's Rural Fire Service.
No one really knows what drives people to light bushfires.
Some, said the institute study, could be simply bored and seeking excitement. Others might want to become a hero fighting his own fire, or overcome a sense of inadequacy with feelings of power and control.
Bushfires could also be started out of anger or revenge, to beat legal bans on land clearing or fuel reduction, or even to earn overtime.
Some arsonists were probably suffering from mental illness.
Whatever the motivation, the potential for harm is enormous.
Although caused by lightning, fires in the Victorian Alps in 2003 show what can happen: burning for 59 days and joining into the largest fire in the state in more than 50 years, flames consumed 1.3 million hectares of land, 41 homes, and 9000 sheep and cattle.
Three years later, in January 2006, 500 fires broke out in conditions similar to those expected this weekend, killing five people, razing 57 homes and 360 farm buildings, 64,200 cattle, sheep and other livestock, 104,000 of national and state forest, and 2500km of fencing.
All of which means Australians loathe firebugs.
As his state burned late last month Victoria state Premier John Brumby vowed to be tough on arsonists, who face up to 25 years in prison if convicted of lighting a fire that kills someone.
"There is no more ... cowardly, destructive act, no more anti-social act, than deliberately lighting a fire to threaten property and threaten people," Brumby said after evidence emerged that an arsonist was behind an inferno in the Latrobe Valley east of Melbourne. Arsonists hit Latrobe with total fire bans in place and fire and emergency crews on 24-hour standby as mid-40 degree days pushed vast areas of the state into extreme fire risk.
Two of their fires were contained before they could do much damage.
But the third raced across grassland, through more than 2000ha of timber plantation, 64 farm sheds and 29 houses in the towns of Yinnar, Boolarra and Mirboo North. Hundreds, possibly thousands, or sheep and cattle were lost. No one knows the toll on native wildlife.
More than 400 firefighters, most volunteers, fought around the clock for days to bring the blaze under control, using 240 trucks, 27 bulldozers and 14 fixed wing aircraft and helicopters.
As investigators moved through the area, police said the fire had been deliberately lit, and offered a A$100,000 reward for information leading to the conviction of the arsonist.
"All of us are appalled by the risk to our communities," Victorian Chief Commissioner Christine Nixon said.
"Given the drought and the extreme heat it is incredibly concerning to see people acting so recklessly by deliberately lighting fires that could result in people dying."
After a decade of drought and a record heatwave, Australia's southeastern states have become tinderboxes. Branches snap from trees. Many other trees split or topple entirely. What vegetation survives on rock-hard plains is brittle. Forests and plantations are thick with fried mulch and dehydrated shrubs and bushes.
It takes the least spark to turn this into an inferno.
All of which has left the great dry continent on edge as another baking weekend starts. Forecasters predict a brutal, lethal heat that will sear even coastal towns and cities normally cooled by sea breezes. Inland areas will become a furnace.
The far western New South Wales towns of Broken Hill and Ivanhoe are bracing themselves for 47 degrees. In South Australia, where a continuing heatwave punished towns in the interior with maximums in the mid- to high-40s over the past few days, Adelaide will again endure a forecast 41 degrees today.
And in Victoria, the relief of isolated drizzle and some coastal sea breezes will vanish as northerly winds return.
As temperatures soar, a firebug's thrills are the last thing Australia needs.
STATISTICS:
50 per cent of Australian bushfires are deliberately lit or start in suspicious circumstances
250 people have died in bushfires in the past 30 years
29 homes were destroyed in Victoria last month in fires blamed on arsonists
