deaths from within the last week or so. why is that so deadly? >> well, they are still looking into specifically what this is. my guess is, after reporting on this and talking to detectives, what happens a lot of times with heroin, they will try and cut it with something else, they will add another substance to make it more potent so they can use less of it and they make more money and a lot of time they cut it with something known as fentanyl. 10 to 100 times, depending on the dose, more powerful than heroin. so the scenario is, someone who is a regular heroin user, an abuser, all of a sudden gets this substance, thinks that they are going to take the same dose as normal and all of a sudden they have an overdose because they have taken a lot more than they have expected to take. >> i remember talking to a heroin expert from john jay college years ago who said oftentimes when there's a particularly potent brand of heroin, people have actually died taking, it becomes more