A Michigan couple was convicted of murder Friday in the death of a five-year-old girl who had pneumonia and weighed just 25 pounds when an emergency crew found her last spring.

Andrew Maison and Hilery Maison, his wife and the girl's stepmother, were found guilty after a six-day trial in St. Clair County, about 95 kilometres northeast of Detroit.

They were accused of abusing, torturing and starving Mackenzie Maison, who was unresponsive when an emergency crew was called to their home in Port Huron last May.

Medical experts said she was malnourished, sick and far underweight. A younger sister was also malnourished but has doubled her weight in foster care since Mackenzie's death.

"It doesn't change what happened and it doesn't bring back Mackenzie," prosecutor Mona Armstrong told the Port Huron Times Herald, referring to the guilty verdicts. "It does serve a measure of justice. But it should never have gotten to this point.

The Maisons face life in prison with no opportunity for parole. They are due in court March 10 for sentencing. 

Hilery Maison's attorney, Michael Boucher, told jurors there was no evidence that the couple intended for Mackenzie to die. Police said the Maisons attributed the weight loss to picky eating.

"We are witness to a horrible, horrible tragedy, all of us. Let's not compound this tragedy," Boucher told jurors.