"Facts are facts," she said. "It's frankly time to put the big boy pants on because, candidly, if you can't handle this, how are you going to handle Roy Barnes?"
The Atlanta Journal-Constitution reported last week that a federal grand jury subpoenaed state Revenue Commissioner Bart Graham over a meeting he had with Deal about the former congressman's lucrative longstanding business relationship with the state.
Deal and his business partner Ken Cronan operate a salvage yard in Gainesville that for nearly 20 years enjoyed a no-bid agreement with the state to provide space for inspections of rebuilt vehicles. The AJC reported in August 2009 that Deal intervened with Graham and other state leaders to stop Graham from changing the program that earned Deal and Cronan's company nearly $300,000 a year.
The newspaper's report led to a congressional ethics investigation that found Deal possibly violated U.S. House rules. Deal resigned from Congress in March before any formal accusation was made.
Deal said he did nothing wrong and told reporters last week that, as far as he knows, he's not the target of a federal investigation.
Handel has come under fire, too. Last week, a complaint filed with the State Ethics Commission accused her of improperly using money from her secretary of state campaign in 2009 to pay for expenses related to her bid for governor.
Deal said Handel has consistently attacked her top Republican opponents because she has so few ideas.
"It's one of those campaigns where everybody is a crook but her," Deal said. "I think that's an indication if you don't have an issue to talk about, try to crucify your opponent."
Handel called ethics a key difference in the candidates.
On taxes, Handel said it was "very realistic" to eliminate the state income tax. The income tax makes up more than half of all state revenue, and the state is already in the middle of a fiscal crisis.
But Handel said, "I reject the notion that you can't do spending cuts without also doing tax cuts."
Deal, who has promised corporate and small-business tax cuts, noted that Handel did not offer any specifics about how she would balance the budget, other than laying off state employees.
However, Deal also has offered few specifics about how he would balance the state budget.
Handel criticized Deal's nearly two decades in Congress, noting that he passed few bills while pulling down $2.5 million in federal pay.
"Did voters get their money's worth?" Handel asked.
Deal responded, "Absolutely. You know, I know you've never served in a legislative body and you don't understand. The most important thing you do in a legislative body is to make sure bad things don't go through."
Highlight statements from Sunday's debate
Handel to Deal on her negative campaign ads: "Facts are facts, and this is a campaign for governor. Things are tough, campaigns are tough, and it's frankly time to put the big boy pants on because, candidly, if you can't handle this, how are you going to handle Roy Barnes?"
Deal: "I think that's an indication if you don't have any issues to talk about, try to crucify your opponent."
Handel on taxes and fixing the state's budget woes: "I reject the notion that you can't do spending cuts without also doing tax cuts. I believe if you reduce taxes, that is how you get your economy moving again."
Deal on Handel's plans: "What you just heard, when you asked for specifics, was the same cliches, the same generalities that we've heard in a canned campaign speech this entire election cycle. I am the only one that is giving you specifics."