A Canberra man charged over an explosion outside the Australian Christian Lobby offices has killed himself.
The 36-year-old died on Sunday.
He was set to fight allegations of arson and property damage at trial, arguing he was mentally impaired when he drove a van packed with gas cylinders into Eternity House at Deakin in 2016.
His defence lawyer, Peter Woodhouse, said on Monday the man's death was further evidence that his alleged offence had "always been a mental-health issue and nothing more than that, despite what those opposite would like to assert".
The lobby's managing director, Lyle Shelton, had said the attack took place in the context of abuse and threats of violence towards his group.
However, ACT Policing said there was no political, religious or ideological motivation behind the explosion.
The man suffered serious burns when he walked five kilometres to Canberra Hospital after the explosion on the night of December 21.
Police said on Sunday they were investigating his death and would prepare a report for the coroner.
The man was charged in April and faced court for the first time in August, when he was committed to stand trial in the ACT Supreme Court.
Mr Woodhouse, of Ben Aulich and Associates, told the court the man did not dispute the facts of the incident but had indicated he would plead not guilty due to mental impairment.
The lawyer said the court would probably have found his client not guilty in the circumstances.
He encouraged anyone struggling to cope with their own problems to reach out for help.
On the night of the 2016 attack, police were called to the Campion Street building after reports of a car fire about 9.30pm.
Officers found the van, parked about one metre from the building, in flames.
A man, who police believed was the accused, was captured on CCTV footage as he walked along a nearby street with his arms outstretched about 10.30pm.
When the man arrived at the hospital's emergency room, staff noticed his hair, face and arms had been badly burned and were blistering.
The man allegedly hired the van from a car rental service at Canberra Airport the previous day, before he drove to a Phillip supermarket and spent $140 on four 8.5 litre gas bottles.In an interview with police the night of the explosion, the man allegedly said he wanted to harm himself.
He told them he wasn't affiliated with any groups and chose the building as he disliked the Christian Lobby because "religions are failed", court documents said.
In the months before the explosion, he allegedly searched the internet for "how to make ammonium nitrate", "pressure cooker bomb", "c4" and "how much gas leak to cause explosion".
His mobile phone also allegedly showed internet searches for "china lgbtq", "israel same sex marriage", "hinduism same sex marriage" and "countries with same sex marriage".
In November, he'd searched "Australian Christian Lobby". He allegedly told medical staff he had driven a van up to a "church", opened four gas cylinders and lit a lighter.
After they ignited, he had walked to the hospital. The man said he was "not a huge fan" of the lobby or religion due to their views on sexuality, but said his decision to drive to the building was "spontaneous" as he couldn't find a suitable spot.
It hadn't been the man's first attempt to take his life, court documents said.
ACT Policing took the unprecedented step of last month publishing a lengthy statement on its website about the case, maintaining police believed the man's primary motivation had been suicide.
"It is important for police to advise the public when an investigation into a terrorism incident has commence," the statement said.
"It is just as important to advise the community where an incident is not believed to be terrorism-related."
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