A former Sydney floor trader has admitted to leading a "double life" in which he would "get boozed at lunch time" and rob banks in the 1970s, court documents show.

Key points: Ross McCarty was only caught more than 40 years after the robberies when police used fingerprint analysis

Ross McCarty was only caught more than 40 years after the robberies when police used fingerprint analysis McCarty told police he would cooperate after he was arrested at his Edgecliff home in 2018

McCarty told police he would cooperate after he was arrested at his Edgecliff home in 2018 He stopped robbing banks and gambling after getting a "really good job" in 1979

Ross Oliver McCarty, 70, last week pleaded guilty in the Downing Centre to four robbery charges related to a string of hold-ups across Sydney in 1977 and 1978.

But it wasn't until 2018 — more than 40 years later — that McCarty was charged after detectives re-opened the unsolved cases and used fingerprint analysis to track him down.

A statement of agreed facts before the court reveals McCarty told detectives his work as a floor trader meant he did not keep strict hours.

"So I'd get boozed at lunch time and go and do it," he is quoted as saying in the agreed facts.

"Those were boozy days … everybody would drink at lunch time."

Last week, two of his charges were withdrawn, while another four — for which he has not yet entered pleas — have been transferred to the District Court.

McCarty was initially charged over eight robberies in which a total of $12,693 was stolen, usually between $1,000 and $2,000 at a time.

The banks he targeted included ANZ, Commercial, the Bank of NSW, National Bank and the Rural Bank.

The agreed facts said that McCarty, in his late 20s at the time, carried a water pistol and wore various disguises including sunglasses and moustaches.

The documents also said he sported felt, tweed, straw or terry towelling hats and produced hand-written notes on withdrawal slips, warning tellers he was armed and demanding they give him sums of cash.

"No funny business," one of the notes threatened.

Detectives used fingerprint analysis on the notes in November 2018 and matched McCarty's prints to ones taken from him in relation to unrelated matters in 2011.

He was arrested the following month at his home in Edgecliff and told police in an interview he was "not going to be clever about it" and would cooperate.

Stock trader led a 'double life'

According to the statement of agreed facts, McCarty said he robbed the banks because he was losing money gambling and needed to cover both that and living expenses.

He said he would go to an illegal casino in Bondi to play blackjack and drink free alcohol.

"I used to lap it up and it kind of snowballed … the more I did the worse I felt about the whole thing and [it] was leading a double life," he told police, according to the agreed facts.

According to the court documents, when asked what he did with his robbery disguises McCarty explained he would "dump those and just walk back to the office".

"Often I'd be passing as the hold-up squad went the other way," he is quoted as saying.

According to the agreed facts, the only person McCarty had ever told about his crimes was his sponsor in Alcoholics Anonymous, who he claimed "took it with him to the grave".

McCarty said he stopped robbing banks when he stopped gambling and got a "really good job" in 1979.

He is due to face the NSW District Court next week.