Timothy Ferguson weighed just 30kg when he died. His mother has been convicted of murder.

Content warning: This story includes depictions of violence that may be distressing to some readers.

It took just one hour for a jury to find a Michigan mother guilty of the murder and child abuse of her teenage son.

Shanda Vander Ark was a mother to three boys, but according to court records, she treated her youngest son, Timothy Ferguson, differently from the others. So differently, he ended up dead. An autopsy revealed the young boy died from malnourishment and hypothermia. His death was ruled a homicide.

When 15-year-old Timothy died, he weighed less than 32 kilograms. 

Watch: The Case Of Keli Lane: From Olympic Hopeful To Convicted Murderer. Post continues below.

Text messages between Vander Ark and her 20-year-old son, Paul Ferguson, revealed her son was complicit in the abuse of his younger brother. 

The pair discussed the various forms of so-called punishment used against Timothy, including feeding him hot sauce, forcing him to take ice baths, depriving him of sleep and locking the refrigerator and food cabinets. 

Vander Ark was also accused of forcing her son to stand against a wall for hours at a time. 

Her lawyer tried to paint a picture of a picture of a hardworking woman carrying the heavy load of single motherhood; a woman weighed down by the difficulties that came with homeschooling a child with some mental challenges. 

"This is a survivor. A person who pulled herself up by her bootstraps," Vander Ark's attorney, Fred Johnson claimed. "We're not looking at evil, we're looking at sick."

But the chief prosecutor, Matt Roberts, rejected that notion, citing the fact that Timothy was treated vastly differently from the other children. The court heard Vander Ark installed security cameras throughout the house, locking the fridge and the panty to prevent Timothy from eating, despite his severe malnourishment. 

"She killed him. She starved him to death," Roberts said.

Timothy was just 15. Image: Courts.

When Vander Ark took the stand for more than three hours, she claimed she couldn't remember much of days, weeks, and even months leading up to Timothy's death. 

During her testimony, Vander Ark was shown pictures of her son's malnourished body. When confronted with the images, she appeared to duck below the stand and throw up several times. 

However, when she was given the chance to speak, she declined. 

Another of Vander Ark's sons, Nolan Ferguson, spoke on behalf of his brother, telling the court if he couldn't have his brother back, his mother shouldn't have her freedom back.

The jury agreed, finding Vander Ark guilty of open murder and first-degree child abuse. She was sentenced to life in prison without the chance of parole for the murder, and an additional 50 to 100 years for the child abuse conviction. 

Her son pleaded guilty to murder and is yet to be sentenced. 

"I've been trying now for this entire case to wrap my mind around how somebody could do something so horrific, not only to another human being but to their own child," Judge Matthew Kacel said.

"You intentionally and systematically tortured this child. Let's call it what it is: It's torture. You tortured this child."

Timothy's family said they found some comfort in the sentence, saying legal justice had been served.

If this has raised any issues for you, or if you just feel like you need to speak to someone, please call 1800 RESPECT (1800 737 732) – the national sexual assault, domestic and family violence counselling service.

Feature Image: YouTube/CourtTV