A woman has pleaded guilty in the death of her toddler son, allowing the abused boy to be kept confined to a St. Bonifacius home’s basement that reeked of raw garbage, rotting food and dead animals until his death in February 2012.

Shacara Foster, 28, admitted to second-degree manslaughter in the death of her 18-month-old son, Cottrell, Tuesday in Hennepin County District Court.

Foster’s boyfriend, Kentae Todd, 22, of Coon Rapids, pleaded guilty to second-degree murder and was sentenced in July to nearly 12 years in prison. Foster will be sentenced Oct. 8, with prosecutors anticipating a prison term of nearly eight years.

An autopsy found that Cottrell had a broken leg and broken arm, a fractured skull, fractured ribs and other bruises. But what killed him was a blood infection caused by a severe burn on his right hand, according to the criminal complaint.

In court Tuesday, Foster acknowledged leaving her son with Todd, and that when she returned home she knew the child had been burned but did not check on him for hours.

On Feb. 9, Cottrell burned his hand. Todd told police he put cold water on the burn and wrapped it. The next day, he gave Cottrell cold medicine for a fever. Todd told police he left the sleeping children to go to a store and later smoked marijuana. Foster returned and found Cottrell not breathing. He was taken to a Waconia hospital, where he died.

The Minnesota Regional Medical Examiner’s Office ruled the death a homicide due to neglect, specifically the infection from his burn.

The autopsy report listed broken bones, cigarette burns on his feet, bruises across his body and brain hemorrhages. Toxicology tests showed high levels of adult cold medicine. Photos, the medical examiner added, depict a “desperately ill, battered and injured child.”

Cottrell’s younger sister had no signs of abuse.