The man accused of the 1994 bombing of the National Crime Authority office in Adelaide talked of conducting an experiment with an "explosive compound" in the months before the blast, a witness has told the Supreme Court.
In his third day giving evidence on Monday, Allan Chamberlain told how Domenic Perre talked to him in late 1993 or early 1994 about how he had detonated the material on a rural property next to a river.
"He said that he set it off," Mr Chamberlain told Perre's trial.
"I understood that he had essentially lit a fuse to initiate the explosion.
"He told me that it didn't go as planned or it didn't go off when he expected it to, and he was walking back to the area from a distance to see why it hadn't gone off and it then exploded.
"He seemed pleased with the results but not pleased with the timing associated with it."
Mr Chamberlain also testified that he later had a conversation with Perre about timing devices with Perre having "some specific requirements" that were "out of the ordinary".
One of those requirements was that the time period be "many hours, perhaps days".
On the day of the NCA attack, Mr Chamberlain told the court he had been in the city and heard ambulance sirens, but didn't think much more about them.
However, when he arrived for work at a suburban gun shop, he heard details of the bombing on the radio.
Earlier on Monday, Mr Chamberlain detailed how he had received a second load of guns from Perre in late 1993 which he stored with a first cache under floorboards in a horse-feed shed at his Adelaide property.
He said one weapon stood out, an M60 which was a fully automatic military-style gun.
Mr Chamberlain said Perre was happy for him to take the weapons out and inspect them but didn't want them fired.
"He seemed relatively comfortable with the fact I could inspect and essentially play with them," the witness said.
Asked how significant the gun collection was, Mr Chamberlain said it was "extensive, very extensive".
The court heard that by this stage, he was hiding enough weapons for Perre to fill two footlockers, along with ammunition, gun magazines and other items.
Perre has pleaded not guilty to the murder of Detective Sergeant Geoffrey Bowen and the attempted murder of lawyer Peter Wallis over the NCA attack.
Sgt Bowen died from horrific injuries, including the loss of his left arm, while Mr Wallis lost an eye and suffered severe burns.
Defence counsel previously told the court that Perre was "explicit" in proclaiming his innocence both immediately after the bombing and in relation to the charges he currently faced.
But the prosecution has alleged the bombing of the NCA office was a personal attack on Sgt Bowen.
In the Crown's summary of the case, Sandi McDonald SC said Perre's hostility towards the detective had grown because of their interactions following the seizure of a multi-million-dollar cannabis crop in the Northern Territory in August 1993.
The trial continues before Justice Kevin Nicholson who is sitting without a jury.
Australian Associated Press
