What does Port Arthur mean to the global gun debate?
Port Arthur is a touchstone in the global gun debate because Australia's worst mass shooting 20 years ago spawned tough laws which are often cited as successful measures when massacres occur elsewhere.
John Howard had been Prime Minister for just six weeks when Martin Bryant embarked on his slaughter at the former convict settlement, leaving 35 people dead and dozens wounded.
Two weeks later, having corralled an agreement out of the states and territories, Howard announced a package of gun reforms including a ban on certain semi-automatic and self-loading rifles and shotguns.
What was introduced?
A uniform and stringent licensing system, including waiting periods, while a national buyback programme of banned weapons resulted in more than 700,000 being surrendered.
Is that still in place?
Fears are growing that the laws are in danger of being wound back. The architect of the 1996 National Firearms Agreement says he remains "wholly against any watering down" of gun laws, and would "encourage a sensible strengthening".
Who or what are threatening the laws?
Several states and territories have moved to lessen controls, including Tasmania, which has removed the cooling-off period for buying a second firearm.
More recently it has emerged that more than 7000 Adler A110 rapid-fire shotguns have poured into the country in the past six months.
What about private ownership?
There have been revelations some Australians have amassed huge private arsenals of firearms. One gun owner, in Cardiff near Newcastle in New South Wales, had 322 registered firearms. More than 100 postcodes in NSW are linked to more than 2400 guns.
Is there still agreement over controls?
The gun debate is polarising. Liberal Democratic senator David Leyonhjelm says gun control laws have already gone too far. "There is an anti-gun push in the Attorney-General's Department (AGD), and it is literally within the Attorney-General's Department, and it's being encouraged by the gun-control lobby to argue for increasing restrictions," Leyonhjelm said last month.
"There have been documents provided out of the firearms and policy working group which shows the ... firearms group in the AGD have had an agenda of incrementally increasing restrictions on firearms."
What about the use of rapid-fire guns?
A new front in the debate has been opened. Gun dealers describe the introduction and publicity around a controversial lever-action Adler A110 shotgun as a game changer.
The Adler, according to documents released by the Attorney-General's Department last year under freedom of information rules, has the capacity "to engage targets quickly with a large ... number of 12G shotgun cartridges".
It has also emerged that gun dealers are already sidestepping the ban on the seven-shot Adler by using a legal loophole that allows them to modify the weapon and boost its magazine capacity.
What has been the reaction to it?
Plans to import a seven-shot version of the weapon were halted last July when it was banned by former Prime Minister Tony Abbott for six months, later extended until August 7 this year, while a review of the National Firearms Agreement took place. That review is considering whether to place further restrictions on the Adler and other lever-action shotguns.
What does Howard believe about the the Adler?
Howard rejects arguments from the gun lobby that the Adler should not face further restrictions. "The Adler lever-action rifle is being argued to be not within the ban and it's really a weapon that doesn't have the lethal capacity of automatic and semi-automatics," he said. "I'm pretty dubious about that."
And the gun laws?
Howard said he remained sceptical about any changes in gun laws in Australia.
"I'll naturally wait and see what the inquiry recommends but anything that to me looks as though it waters down the laws that are in place now I won't support and I will argue that the Government shouldn't support because the experience with these things is when you've had a ban in for a long period of time and it's worked.
"This ban has been so successful, and is so widely respected around the world, that I would not want any government in Australia to do anything that would weaken it."