By Michael Balsamo and Geoff MulvihillThe Associated PressWASHINGTON — Drugmaker Purdue Pharma, the company behind the powerful prescription painkiller OxyContin that experts say helped touch off an opioid epidemic, will plead guilty to federal criminal charges as part of a settlement of more than $8 billion, the Justice Department announced Wednesday. The deal does not release any of the company’s executives or owners — members of the wealthy Sackler family — from criminal liability, and a criminal investigation is ongoing.Read more on NewsOK.com