A California man is in custody in Omaha after being found in possession of enough of the opioid fentanyl to kill nearly five million people. Acting US Attorney for the District of Nebraska says the seizure in Omaha is one of the largest ever in the country. Edgar Navarro-Aguirre was arrested Wednesday, accused of transporting more than 33 pounds of the drug. Fentanyl is about 50 times more potent than heroin. Experts say it only takes about three milligrams for the drug to be fatal. With that in mind, the amount seized would be enough to kill about the entire populations of Iowa and Nebraska.