He was pulled over by the police. He consumed the Fentanyl he had in his possession. Fentanyl is a anesthetic. If you administer it intravenously it has a immediate effect. If you consume it orally it will take longer to take full effect. Eventually, it will knock out your respiratory drive. I imagine as it is slowly absorbed via your gastrointestinal tract you will begin to feel like you cant breath. I work in the medical field and administer Fentanyl to my patients daily. Typically it is given intravenously. If your patient does not have venous access and you need to intubate, it can be given intranasally. Also, when you have a patient who is intubated, on a ventilator and they begin to desaturate, you want to sedate them and reduce oxygen consumption through work of breathing. Paralyzing your patient is the best way to improve their oxygen saturation as long as they are on life support. The autopsy said he had fentanyl in his system, it will kill you.