Fallen football legend O.J Simpson, cleared more than a decade ago of killing his ex-wife, may now end his days behind bars after being jailed for up to 33 years on Friday for armed robbery and kidnapping.

After analysing Judge Jackie Glass's complicated sentencing for 10 convictions, Simpson's lawyers said the minimum time the 61-year-old could serve before being eligible for parole would be nine years, and the maximum would be 33.

Earlier Simpson had apologised to the judge for the September 2007 robbery at the Palace Station hotel in Las Vegas.

'I am sorry'

"I did not know that I was doing anything illegal. I thought that I was confronting friends and retrieving my property. So I am sorry. I am sorry for all of it," Simpson said, his voice trembling as he fought back tears.

Simpson was found guilty for his role in the 2007 raid in which he and five friends, two of them carrying weapons, stormed a room in the Las Vegas hotel, locked the doors and robbed two dealers of a trove of sports memorabilia.

Simpson, shackled and dressed in a blue prison uniform, said he had been trying to get back personal items he said had been stolen from his family.

"Property that over the years we have seen being sold on the Internet, and we have seen pictures of ours that were stolen from our home going into the tabloids," he said.

But Judge Glass dismissed Simpson's excuse that he had acted out of stupidity. "That was actually a very violent event," she said.

"Guns were brought, one was displayed. The potential for harm to occur in that room was tremendous... This was not just a legitimate 'give me my stuff back'. This was something else," Glass said.

Sentences to run concurrently

The heaviest single sentence she imposed was 15 years for each of two charges of kidnapping to run concurrently.

His co-accused Clarence Stewart (54) who took part in the raid, was also sentenced to 15 years for the same charges, as emotional friends and relatives looked on from the public gallery.

Simpson's 3 October conviction came 13 years to the day after he was acquitted in his controversial 1995 trial of murdering his ex-wife Nicole Brown Simpson and her friend, Ron Goldman.

"It's kind of a bittersweet moment knowing that that S.O.B. is going to be in jail for a very long time," said Fred Goldman, the father of Ron Goldman.

"He'll never change, and he's going to stay in jail for a very long time," he said, before adding: "There is never closure. Ron is always gone."

Simpson said among the items he had been looking for was a picture of his son in the Oval Office and his daughter's mother's wedding ring.

Grounds for an appeal?

Defence lawyer Yale Galanter confirmed that Simpson intended to appeal the verdict on several grounds, including that he was tried by an all-white jury.

Despite Friday's heavy sentences, Galanter said that "it could have been worse," since kidnapping carries a maximum life imprisonment.

"After all the numbers and all the calculations, the minimum sentence imposed was nine years," according to Galanter.

"The top end is 33 years. He'll have his first parole hearing after six years, and then there are two 18-month sentences after that."

Galanter said Simpson was clearly upset by the prospect of prison, "but I think he's really relieved he didn't get a life sentence."

It remains unclear whether Simpson will have good grounds for an appeal, which co-counsel Gabriel Grasso said would take about a year.

But Las Vegas criminal defence attorney David Chesnoff said co-accused Stewart may have a better case because his lawyers had asked from the start for a separate trial to avoid being tainted by Simpson's notoriety.

District Attorney David Roger said both defendants had been offered plea deals during the trial that would have given them shorter prison sentences, but did not offer further details.

One of the most famous American football players of his generation during a glittering 1970s career, Simpson was the prime suspect in the 1994 brutal murders of his ex-wife and her friend.

Nicole, who had divorced Simpson in 1992 citing his "abusive behavior," was attacked so savagely she was almost decapitated.

Simpson, who has always vehemently denied the killings, was acquitted after the racially charged 1995 trial, in a verdict that was greeted with widespread outrage across America.

He was subsequently found liable for the deaths in a 1997 civil suit and was ordered to pay damages to the victims' families totaling $33.5-million. He has repeatedly said he will not pay the settlement.