Karch also called into question the fentanyl overdose death of one woman who suffered from migraines. He noted recent research has shown fentanyl accumulates in fat and as the body disintegrates after death the drug is released from deep fat storage.
He likened it to marijuana, which also accumulates in fat and is slowly released back into the body. That is why people taking a drug test for a job can test positive for marijuana even though they may not have used marijuana for three weeks, he said.
"When you talk about toxic, the first thing you need to know is that is a term you use for live people," Karch said, adding that nothing is toxic for dead people.