A picture shows “papa”, as he was known to them, relishing his freedom after being released from Alcatraz where he served over seven years for tax evasion.

That picture is among 174 items belonging to the Capone family that will go up for auction in Sacramento, California, on Friday.

The items range from personal photographs to firearms to pocket watches and jewellery as well as furniture and kitchen ware.

Al Capone’s platinum and diamond Patek Philippe pocket watch is listed for US$25,000 to US$50,000, while his favourite Colt .45 pistol is estimated to fetch US$100,000 to US$150,000.

A vintage hand-coloured silver print of Al and his son, Sonny Capone, is expected to go for $10,000 to US$15,000.

Diane Capone, 77, the second of Al Capone’s four granddaughters, said the decision to sell the items was based on her and her sisters getting older, as well as the increasing threat of wildfires to their homes in Northern California.

Brian Witherell, consignment director at Witherell’s Auction House, said nearly 1,000 bidders have registered for the auction from every U.S. state and 11 countries.

“The items that generate the most interest are the ones that you think of synonymous with a gangster figure like Al Capone, his guns and his fancy flamboyant jewellery,” he said.

Diane Capone said she hopes these items will reveal the human side of her grandfather, instead of the ruthless violence that plagued Chicago in the 1920s for which he has become infamous.

The item that most exemplifies this, she said, is a personal letter Al Capone wrote to his son, Sonny Capone, from Alcatraz estimated between US$25,000 and US$50,000.

“It’s such a lovely letter, and it is a letter that conveys a side of this man that the vast majority of people have no idea of,” she said. “These are not the words or the ideas of a man who is a ruthless gangster. These are the words of a loving father.”