PHILADELPHIA (AP) — There’s been a string of disturbing deaths in Philadelphia involving parents who allegedly fail to feed vulnerable children.

In the most recent case, 30-year-old Carlos Rivera and his 27-year-old wife, Carmen Ramirez, face a preliminary hearing on murder charges in this month’s death of their disabled 3-year-old daughter. Authorities say Nathalyz Rivera weighed just 11 pounds and had not seen a doctor in more than a year.

The other case involves a boy who spent half his life in foster care. Police say Khalil Wimes died of abuse and malnutrition at age six, three years after he was returned to birth parents Tina Cuffie and Latiff Hadi.

A relative testified that he was forced to stand in the corner for hours if he vomited and had to run laps the day before he died.

Khalil Wimes’  brother, Aaron Cuffie, testified Wednesday at the opening of his mother and stepfather’s murder trial.

Twenty-eight-year-old Aaron Cuffie testified that his brother often collapsed during the punishment. Cuffie says he urged his mother to take Khalil to a hospital.

Relatives who raised some of Tina Cuffie’s 11 children sobbed as they heard about the boy’s final years.

Defense lawyers say their clients may be guilty of neglect but not murder.

(© Copyright 2013 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)

Top Content On CBSPhilly