Since January, millionaire Colin Chisholm has sat in jail, claiming he was too poor to post bail. Through the months, he has repeatedly denied charges that he and his wife, Andrea, collected more than $167,420 in fraudulent medical and food-stamp claims over seven years.

On Monday, a very contrite Chisholm agreed to a 21-month prison sentence and admitted that he committed a major economic crime. Speaking barely above a whisper in a Hennepin County courtroom, he told Judge Lois Conroy that "I take full responsibility for this."

According to state guidelines, the presumptive sentence would have been probation and no prison time. But the prosecution argued that the dollar amount of the theft, the length of time over which it occurred and the frequency of the crimes called for an upward departure.

Although Chisholm, 62, pleaded guilty to theft by swindle of over $35,000 and wrongfully obtaining public assistance, he is contesting the amount he is accused of taking. His sentence also includes restitution.

"When he sat down with his attorney and looked at the enormous amount of documents we've obtained that clearly indicate his guilt, he really had no choice but to agree to the plea," said Hennepin County Attorney Mike Freeman. "He surrendered."

Andrea Chisholm, 54, pleaded guilty in August and will finish her jail sentence next month. Freeman said that she was less culpable than her husband, who was forging signatures on documents.

"It was his scheme," Freeman said. "This is a con worthy of 'The Sting.'‚ÄČ"

The couple were living in a $1.6 million mansion in Deephaven on Lake Minnetonka and owned a million-dollar yacht during part of the time they were illegally receiving welfare and other benefits in Minnesota and Florida from 2005 to 2012.

The Chisholms were arrested in March after fleeing Minnesota for the Bahamas. The couple, who once referred to themselves as Scottish nobility, "Lord and Lady Chisholm," claimed to have $97 million in assets and tried to start a satellite television network in the Caribbean.

In March 2012, the Chisholms' benefits were finally cut off when they couldn't explain how they were able to pay their rent and personal expenses with no income. The couple had more than $3 million in bank accounts while they were receiving welfare payments, authorities said.

Colleagues and friends helped police track down the couple in the Bahamas. In court, Andrea Chisholm admitted authorizing various welfare benefit applications filled out by her husband.

But Colin Chisholm appeared to be heading toward a trial. He had discharged his attorney and was appointed a public defender. He also claimed that media reports about his crimes were false.

On Monday, he admitted to filing more than a dozen false applications "for benefits I wasn't entitled to." Freeman said his case was one of the most offensive his office has prosecuted.

"He lived like a king and stole like a pauper," Freeman said. "He was living on a yacht and entertaining royalty. All the while he was cheating the taxpayers and committing other wrongdoings, many of which didn't occur here."

The county attorney said Colin Chisholm has been a con artist for 25 to 30 years.

Freeman said he was professionally satisfied with the sentence, but he was sad to see "someone who was clearly talented waste his abilities on cheating people." Chisholm not only cheated the government and taxpayers but others who believed in him, Freeman said.

Chisholm will be officially sentenced in January. As far as the amount prosecutors determined the couple stole, Freeman said, "there isn't a whole lot of question about it." The only question is how long it will take to collect it, he said.

"We did our job right and we stopped a real con artist," he said. "We prosecute a lot of poor people who commit crimes. A lot of rich people commit crimes, too. We got two of them, and they paid the piper."