Autopsies are not required for federal prison deaths that are classified as natural. NPR found cases where medical neglect, poor prison conditions and a lack of resources contributed to these deaths.

Lawmakers are urging the federal Bureau of Prisons to address prisoner health care after an NPR investigation detailed the stories of prisoners nationwide going without needed medical care.

The Butner federal prison complex in North Carolina is where a quarter of federal inmate deaths occur. It includes a medical facility but inmates aren't getting needed care, there or at other prisons.

President Joe Biden is announcing he has granted the first three pardons of his term, including pardons for two people who were convicted on drug-related charges in Texas and Georgia but went on to become pillars in their communities.

The Bureau of Prisons said Saturday it was securing all of its facilities as a precautionary measure. The agency did not specify the length of the lockdown, but said it was a temporary measure.