Prosecutors rested their campaign fraud case against John Edwards on Thursday after 14 days of dramatic and often unflattering testimony that focused on the once-promising politician's infidelity and the secret money they say he used to cover up the affair he feared would derail his presidential ambitions.

In its final act, federal prosecutors played a tape of a 2008 national television interview in which the Democrat repeatedly lied about his extramarital affair with the woman who was part of his campaign staff and denied fathering her baby.

The testimony repeatedly showed an unappealing side of Edwards, casting him as a liar and lousy husband. The question is whether prosecutors showed he violated campaign finance laws in using nearly $1 million in undisclosed payments from two wealthy campaign donors to hide his pregnant mistress as he sought the White House.

To prove their case, the government has to not only show that the ex-North Carolina senator knew what the money was being used for, but that he knew he was violating the law and did it anyway.

"The case is weak," said Kieran J. Shanahan, a former federal prosecutor turned Raleigh defense lawyer who has been attending the trial. "They've not shown criminal intent."

On Friday, Edwards' defense team will have its turn and plans to ask U.S. District Court Judge Catherine C. Eagles to dismiss the case for lack of evidence. Such motions are routine in criminal trials after the prosecution rests, and they very rarely work. The 58-year-old Edwards has pleaded not guilty to six criminal counts and faces up to 30 years in prison if convicted.

"The prosecution's evidence is good enough to get to the jury, but conviction remains an open question," said Steve Friedland, a former federal prosecutor and professor at Elon University School of Law who has attended the trial. "The case is largely built on circumstantial evidence. There is no smoking gun."

If the judge allows the trial to go forward, the defense will begin presenting its side Monday _ and may call his mistress, Rielle Hunter, to testify. Edwards could also take the stand in his own defense.

Edwards carried on a two-year affair with Hunter _ a videographer who was recording him on the campaign trail _ even as he renewed his marriage vows to his cancer-stricken wife. After his mistress became pregnant, Edwards allowed his right-hand man, Andrew Young, to claim paternity so he could keep up his lofty political ambitions. And he lied repeatedly to his now-deceased wife, his advisers and the public, according to testimony.

After years of adamant public denials, Edwards in 2010 acknowledged paternity of Frances Quinn Hunter, who is now 4 and lives with her mother in Charlotte.

As prosecutors wrapped up their case, they showed the jury records that detailed the money spent to hide Hunter _ $319,500 in cash, luxury hotels, private jets and a $20,000-a-month rental mansion in Santa Barbara, Calif. The bills, flashed up on a large screen for the jury to see, were all paid by Fred Baron, a wealthy Texas lawyer who served as Edwards' 2008 campaign finance chairman.

Phone records introduced into evidence at trial show Edwards was in frequent contact with Baron and Hunter while she was in hiding. A former campaign aide testified he overheard Baron telling Edwards that he was moving Hunter around so the media couldn't find her, while a former speechwriter testified Edwards told her he had known about the finance chairman's support "all along."

Edwards has denied he knew anything about Baron's support for Hunter.

"I've never asked anybody to pay a dime of money, never been told that any money's been paid," Edwards said in the 2008 interview on ABC's Nightline. "Nothing has been done at my request. So if the allegation is that somehow I participated in the payment of money _ that is a lie."

Baron began paying the expenses after tabloid reporters tracked down the pregnant Hunter in Chapel Hill, where she had been secretly living in a house rented for her only a few miles from the Edwards family estate. Hunter was being closely watched over by Young, who falsely claimed paternity of his boss' baby as the tabloid prepared to expose the affair.

As part of the cover-up, Baron paid for Hunter _ and Young and his wife _ to cross the country on private flights worth more than $80,000 and stay in waterfront hotel suites costing nearly $44,000, including bar tabs and frequent room service. Baron also leased a mansion in Santa Barbara for the mistress as she prepared to give birth, with total costs over the next eight months totaling $184,378.

At the time, individual contributions to federal campaigns were limited by federal law to $2,300 per election cycle. Baron had already provided Edwards' campaign the maximum.

In addition to the money from Baron, there was another $725,000 provided by 101-year-old heiress Rachel "Bunny" Mellon to Young. Mellon agreed to support Edwards' personal needs "without government interference" after he took heat for a campaign finance report showing he spent $400 on a haircut. Mellon was never told what the money she gave was being used for.

Edwards denies knowing about the secret payments, which his lawyers contend were gifts from friends looking to help him rather than campaign contributions. Federal law defines a campaign contribution as any gift or payment provided to influence the outcome of an election.

Some of the "Bunny money" went to pay for Hunter's medical bills, buy the mistress a BMW and pay the rent on her North Carolina rental house. Young, who has an immunity agreement with prosecutors, acknowledged on the witness stand early in the trial that much of the cash was siphoned off to build his family's $1.5 million dream house. Baron also helped pay for the house, wiring $325,000 directly to Young's homebuilder.

Much of the money was spent after Edwards suspended his campaign at the end of January 2008 following a string of losses in the early primary states. Prosecutors contend it was still campaign money because Edwards had aspirations of becoming vice president or attorney general.

Prosecutors rested their case Thursday without calling Hunter to the witness stand, though like Young she has an immunity agreement with the government.

Shanahan doubts the defense will call her, either.

"To bring her in and put her face-to-face with the jury would do more harm to the defense than good," the former prosecutor said.

But he predicted Edwards, who made a fortune as a personal injury lawyer before turning to politics, will choose to testify.

"As a defense lawyer, I've represented both politicians and lawyers," Shanahan said. "They always take the stand."

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Follow AP writer Michael Biesecker at twitter.com/mbieseck