On Thursday, as the Casey Anthony trial neared its end, a woman claimed to be Caylee's grandmother, thereby putting an end to the mystery behind Caylee's father's identity.

A 47-year-old woman from Rutland, Massachusetts said she is “100 percent certain” that she is the grandmother of Caylee Anthony and in order to prove it, she's also ready and willing to go through a lie-detector test and a DNA test, the Daily Beast said.

Donna MacLean gave a series of interviews, saying her son Michael Patrick Duggan told her on phone that he fathered a little girl and he had named the Anthony parents before he died in a car accident on October 27, 2007.

“I would never in a million years bring something like this forward if I wasn’t 100 percent positive,” MacLean told the Daily Beast. “My son wouldn’t lie to me.”

According to MacLean, who is now homebound because of back and hip disability, she and her son Duggan always kept in touch. During a conversation on phone in late summer of 2007 , “we were talking about the upcoming birth of my other son’s baby boy,” MacLean said. “I said I had really hoped for a baby girl grandchild, and that’s when Michael told me that he already had one.” At that time, Caylee would have been close to 2 years old.

“I asked him about the circumstances… who is the family? He said the parents were George and Cindy Anthony. I asked who she was and he said her name is Casey. He told me her dad was a cop and I said, ‘Oh, Mike! Does she want child support?’” MacLean said. In those days, Duggan was working as a low-paid waiter in Passaic, New Jersey.

When Casey Anthony trial became hot, MacLean remembered the previous conversation with her son about her granddaughter. After MacLean saw Caylee's photographs, she said “She looked so much like my family, like I did when I was little. The big eyes … I just kept staring into those big brown eyes.” MacLean also has brown eyes like her son Mike.

“I remembered Mike had said Casey offered that if he came back to town they could all ‘crash at a friend’s house.’ Michael thought it was cool,” MacLean said.

According to Daily Beast, Duggan also have complicated family background - his parents are divorced and his father even had undergone a sex-change operation. His father is now in jail in Florida for serious DUI violations.

Duggan wandered South after high school, first to an uncle’s home in North Carolina, and then on his own.

“He was living in Tennessee, working for a moving company [when Caylee was conceived],” MacLean said. “He was traveling all over the region moving households of furniture.” It had become “routine for him to visit Florida,” MacLean said. His paternal grandparents had regularly taken him to visit friends who lived near Disney World in Orlando.

Duggan died in a car accidents in 2007 at the age of 24, according to Falmouth police. His stepsister, Sarah Duggan, a passenger, also died as a result of the crash.

Duggan’s grandfather, Thomas J. Camarota, 81, of East Falmouth, told the Herald on Thursday that he supports his daughter’s effort of finding out the truth.

“My daughter’s within the right of looking up and making sure she’s the grandmother of this child,” Camarota said. “I support her one hundred percent.”

Talking about his dead grandson, Camarota said Duggan was a hard-working guy who sported a grin that said “Look out! I’m Mr. Mischief” when he was a little boy.

MacLean insists she wants nothing but information. “I can’t just walk away. I’m trying to do this peacefully without raising a ruckus,” she says. “I would never in a million years bring something like this forward if I wasn’t 100 percent positive. My son wouldn’t lie to me.”

“All I want is to know the truth,” MacLean adds. “I’ve grieved for my son and now I want to grieve for my grandchild.”