Geremy Justus, aged 38, of no fixed address, went to AIB on St Patrick’s Street on March 27 and handed a note to the employee.
Inspector Adrian Gamble said the note stated: “This is a robbery. I have a bomb in my bag. Give me the money or I will kill us all.”
Justus pleaded guilty to attempted bank robbery.
Frank Buttimer, solicitor, said that half an hour after the ill-fated crime, Justus gave himself up at Bridewell Garda Station and confessed to what he had done.
Mr Buttimer said that with no disrespect to his client, it was clearly a harebrained attempt at a robbery.
“He ended up in Cork, he ran out of money, not least because of his alcohol addiction. And he came up with this most unusual idea. It could never have been successful,” he said.
Mr Buttimer said that apart from passing over the note, there was no physical confrontation and Justus left empty-handed.
He said Justus had been psychiatrically assessed during his remand in Cork Prison.
He had suffered post-traumatic stress disorder as a result of violence witnessed as a child and suffered from alcoholism.
Judge Olann Kelleher adjourned sentencing to Friday so the victim could have an opportunity to describe the impact of the crime on her.