Recreational marijuana is now legal in Massachusetts, but it is not on the federal level, creating obvious confusion for potential marijuana consumers here and for federal law enforcement officers like U.S. Attorney for Massachusetts Andrew Lelling. He has the power to stop this new industry before it ever blooms, but he says that is not his plan. WGBH's Morning Edition host Joe Mathieu talked with him about this in his office at the Boston Federal Courthouse. The transcript below has been edited for clarity.

Joe Mathieu: I'm assuming that your viewpoint has not changed here because you don't have an option to change it. But the question that I hear a lot from people is, 'Am I going to get in trouble if I buy pot that the state tells me is legal and the federal government says is not?'

Andrew Lelling: Well, as I've said before, I can't categorically immunize everyone in Massachusetts from federal marijuana enforcement. What I can say, is marijuana enforcement is not the priority of my office. Opioids is the priority of my office. So if people are fearing a sudden widespread crackdown on purchase and use of small amounts of marijuana, they will not see that from my office. I have about 16 drug prosecutors and I can tell you that pretty much all of them are focused on the opioid epidemic that is ravaging the Massachusetts population.

Mathieu: So let's talk about that a little bit, because that's a pretty big deal and it's something that you're deeply invested in, I know. I tend to talk to lawmakers, policymakers about the pharmaceutical side and we have seen some legal action against the pharmaceutical industry. You're coming at this, as well, from a different side and that would be the source, the supply of opioids.

Lelling: Right.

Mathieu: Is this a cartel issue?

Lelling: Yes, it is a cartel issue, meaning that what we see is a tremendous amount of fentanyl — which as you know, is a horribly deadly narcotic drug — is manufactured in China or in Mexico. But in both instances, the drug goes from Mexico, often to the Dominican Republic, and then to the east coast of the United States, and then up to our region. So there is cartel involvement in the heroin and fentanyl trade. There's also the use of prescription pills by trading, sharing, theft of prescription pills. You also have a mail ordering problem. It is the simple truth that the customs personnel can't monitor all the international mail packages that come into the United States. It's as easy as hopping on the Internet, going to a certain website, ordering pills. They get shipped in a brown paper wrapper, and maybe customs catches them and maybe customs doesn't catch them. Maybe customs catches one in 10, which would be a pretty good rate, but the rest get through.

Mathieu: When we talk about organized crime now, people think of street gangs, MS-13 and so forth driving this. You just finished a case with a very different kind of organized crime. It's almost old-fashioned at this point, when you think of the Salamme case. We're talking about Frank Salemme and Stephen Flemmi — it's like another time. Is the sun setting on that kind of organized crime, the old mafioso stuff, or is this something that your office is still pursuing?

Lelling: No, I think the sun is setting on that kind of crime. Watching this trial was like a little bit of a time warp. I think most of the witnesses were, you know, in their 80s. You're talking about a completely different era in organized crime in Boston which appears to now be closing. The LCN — La Cosa Nostra — is not what it used to be in New England. These days I think it's safe to say it's almost non-existent in New England. The powerful organized crime families just aren't around anymore. Unfortunately, it's been replaced by more violent, more erratic street level gang activity like MS-13. But you really don't see the traditional Mafia model anymore, or at least not much in Boston or in New England.

Mathieu: Do you hope that with the conversation we're having about opioids and just had about marijuana, that the legal side of this marijuana story might help to eliminate a black market, or is that wishful thinking?

Lelling: I don't think it will eliminate a black market. If I understand you correctly, the question is legalizing it for recreational use, will that tamp down on illegal sales?

Mathieu: - And that was the argument to legalize it, right? Or one of them.

Lelling: And I think it will tamp down, of course, on illegal sales of small amounts of marijuana in Massachusetts. But when you look at other states that have legalized marijuana in the past, like Oregon, Colorado — and I've done this to sort of get a sense from their experiences of what federal law enforcement might be facing after marijuana is legalized — there is a tremendous overproduction problem. So what happens is when states legalize marijuana production, certain entities or people will set up marijuana grow operations which now can operate legally in plain sight, but they grow more marijuana than they are supposed to, and they sell the overage in a different state on the black market. So for example in Oregon, once recreational marijuana became legal, there was a surge in illegal marijuana sales in neighboring Idaho. I think Massachusetts will have that problem. And so overproduction will be something that we focus on. I'm the chief law enforcement officer for the District of Massachusetts and I have a counterpart in New Hampshire and a counterpart in Maine. And so we think of it on sort of a state by state level. But the DEA will operate, for example, more regionally. They will be following patterns of marijuana trafficking from Massachusetts to New Hampshire to Vermont or to wherever else.

Mathieu: And they're informing your office?

Lelling: Yes. And my prediction is that we will have overproduction cases, meaning we'll have cases where bulk marijuana is being moved from a legal grow operation in Massachusetts, over a state line and then sold for cash in a neighboring state. And I think we're going to have a role in that kind of enforcement.

Mathieu: I have to admit, it seems like it's putting a huge burden on prosecutors like yourself to balance these disparate laws on the state and federal level.

Lelling: It puts us in an extremely awkward position because residents of the state of Massachusetts ... many of them, not unreasonably, think that after July 1, buying and selling marijuana is legal — it's not. There's a federal law that specifically prohibits buying and selling marijuana. And so it creates this odd situation for federal law enforcement. And I think it's true, there appears to be a nationwide trend toward some kind of legalization. I think that we in federal law enforcement have to be careful about how we tread here. While I do not anticipate some kind of widespread crackdown on the use of small amounts of marijuana in Massachusetts, we'll have to figure out exactly what role we want to play that tries to complement or control, in some ways, the proliferation of marijuana growth and use on the state level.