Mr Bisucci, who had only recently moved in with his partner, was the subject of a long-standing firearm prohibition order.
Marilyn Burdon, who was shot dead by her partner in a suspected murder-suicide in Kew in 2017.
On Monday, Sebastian Carmuciano, a 70-year-old maintenance cleaner from North Coburg, told day one of an inquest into Ms Burdons death that he was doing Mr Bisucci a favour when he transferred some of his friends guns into his own name after Mr Bisuccis gun licence was removed in the mid-2000s.
Mr Carmuciano told the coroner he remembered signing a large number of blank documents for his former neighbour, which allowed him to circumvent the prohibition notice and move the guns around the state, before one was later used to kill Ms Burdon.
I signed blank forms and he filled out all the details of the guns, Mr Carmuciano said. Charles had arranged for the firearms to be placed in my name and I signed some papers at the time.
He didnt want his guns destroyed, thats why he transferred them into my name.
Mr Carmuciano, who appeared highly agitated and at times confused during questioning, said his friend was persuasive and he believed him to be a lawyer, despite Mr Bisucci being barred from practising some years earlier.
Officers at the Kew home where the bodies of Mr Bisucci and Ms Burdon were found.Credit:Chris Hopkins
The witness said he knew his friend had his firearms licence suspended, and he took legal ownership of three of the firearms in 2007 and a further three in 2008 as a favour.
In 2012, when his former neighbour came knocking, Mr Carmuciano let him and a friend leave with the guns.
When pressed about a series of documents appearing to have his signatures on them, including change-of-address details and a licensing upgrade application, he claimed most had been fraudulently signed.
The others, he said, he signed when they were still blank.
You were pretty reckless about how you went about it by signing a blank form, counsel assisting the coroner, Naomi Hodgson, said.
Mr Carmuciano replied: Im a human being, human beings make mistakes. I did not authorise him to produce these documents, I cannot believe all of this.
Ms Burdon, whose three children were present at Mondays hearing, was a grandmother of five and had a masters in criminology, working in crime prevention with Melbourne councils.
The coroner previously heard that at the time of the deaths, Mr Bisucci was the subject of a firearm prohibition order after a separate incident of family violence many years earlier, which resulted in police seizing 16 guns from his Melbourne home.
The seized weapons were said to have included a .33 Winchester lever-action rifle. Police say this was the weapon used to kill Ms Burdon more than a decade later.
Witnesses due to give evidence at the inquest include Mr Bisuccis lover, Karen Cattapan, and a leading forensic domestic violence expert. The inquest continues.
Anyone needing support can contact Lifeline on 13 11 14. The national domestic violence helpline is on 1800 RESPECT. In case of emergency call 000.
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