The practice of giving sedatives to people detained by police has spread quietly across the nation over the last 15 years, built on questionable science and backed by police-aligned experts, an investigation led by The Associated Press has found.

When a 24-year-old former Marine experienced a manic episode at a southern Indiana rest stop, his mother called 911 for help getting him mental health treatment.

FRONTLINE and The Associated Press investigate deaths that occurred after police used tactics like prone restraint and other “less-lethal force.”

Over a decade, more than 1,000 people died after police subdued them through means not intended to be lethal, an investigation led by The Associated Press found.