Wilmington, N.C. — The maternal grandmother of a boy who died last year after spending the night tied to a tree said Tuesday that the plea deals his father and stepmother received are an injustice.

Brice McMillan and his wife, Sandra McMillan, were sentenced Monday to no more than 16 years in prison each for the June 12, 2008, death of Tyler McMillan.

Tyler, 13, died of dehydration and heat stroke after being tied twice to a tree as punishment for disobedience, authorities have said. The second time, he was left outside overnight.

His parents were charged with first-degree murder and felony child abuse, but they pleaded guilty to second-degree murder this month under an Alford plea – meaning that they maintain their innocence while acknowledging that prosecutors had enough evidence to possibly win a conviction

Sandra McMillan was sentenced to 13 to 16 years in prison, while Brice McMillan was sentenced to 10 to 13 years.

Both tearfully apologized during their sentencing, saying they never meant for the boy to die.

"I think he's a sorry excuse for a man, and I think he's a sorry excuse for a father," said June Sasser, of her grandson's father. Sasser’s daughter Mickie was Tyler’s mother. She died of cancer in 2004.

Sasser said that she was stunned by the sentences, adding that they are far less than those involved in financial scams, such as financier Bernie Madoff, who was sentenced Monday in one of the biggest financial frauds in history.

"He gets 150 years. Two people kill a child in a god-awful way – they get 10 years?" Sasser said.

Brice McMillan married Sandra McMillan after the death of his first wife and the couple, Tyler and his younger brother lived in Macclesfield.

Sasser said she rarely saw her grandsons after the wedding and claimed that Sandra McMillan threw out all reminders of the boys' mother, including photos and family Bibles.

She learned of Tyler's death, she said, from her son-in-law, who called her from jail.

"In a very flat dead monotone voice, (he said), 'Tyler's dead, and I've been arrested for first-degree murder, and I'm in jail,'" Sasser recalled.

After Brice McMillan pleaded guilty earlier this month, Sasser said, she started an online petition and wrote to the Edgecombe County district attorney's office urging prosecutors not to offer a deal to Sandra McMillan.

Prosecutors said in court Monday that they offered the pleas because they did not believe the McMillans intended to kill Tyler and that the deal was in the best interest of all involved.

Sasser disagrees.

"What did they think was going to happen?" she asked. "Maybe they weren't trying to kill him, but they were sure trying to hurt him."

After fighting so long for justice, Sasser said she will now focus on preserving her grandson's memory.

"He was just one of the most sweetest and loving young men I've ever seen," she said.