CBS Evening News | Dr. Neil Capretto, medical director of Gateway Rehab in Pennsylvania, tells Vinita Nair about the dangers of the drug fentanyl

Dr. Neil Capretto, medical director of Gateway Rehab in Pennsylvania, tells Vinita Nair about the dangers of the drug fentanyl, a powerful painkiller that when mixed with heroin can prove fatal. Air Date: Feb 1, 2014