The trial of Tina Cuffie, also known as Tina Wimes, and Latiff Hadi, also known as Floyd Wimes, had started on Wednesday.
Khalil Wimes weighed less than 30 pounds when he died in March 2012.
They now face at least 20 to 40 years in prison when they are sentenced Nov. 26.
Khalil was the second-youngest of his 45-year-old mother's 11 children. At least five were removed from her care.
At the opening of the trail, Khalil's brother testified the boy was forced to stand in the corner for hours as punishment for vomiting and had to run laps in a hallway the day before his death.
Defense lawyers conceded at the nonjury trial that their clients may be guilty of neglect, but they challenged the murder charge and suggested that Khalil's vomiting affected his weight.
They attributed his scars and bruises to falls, eczema and bedbug bites.
Khalil frequently vomited, leading the parents to lock him in his room at night so he could not get up and eat, according to testimony and photographs of the exterior bolt.
He was also spanked and struck with a belt, according to the older brother. And he was home-schooled - unlike his younger sister - and spent much of the day in his room.