A group of prosecutors, including Suffolk County District Attorney Rachel Rollins and Middlesex County District Attorney Marian Ryan, have filed a lawsuit in an attempt to bar ICE from making courthouse arrests. The move comes shortly after Newton District Court Judge Shelley Joseph was charged with obstruction of justice. She is accused of helping an immigrant evade ICE custody. Morning Edition host Joe Mathieu spoke with Northeastern University law professor and WGBH legal analyst Daniel Medwed about what these two recent cases could mean for Massachusetts' relationship with the federal government. The transcript below has been edited for clarity.

Joe Mathieu: How unusual is it for a state judge, in this case Shelley Joseph, to face federal criminal charges?

Daniel Medwed: It's very unusual, and here's why. First, we have a state court judge facing federal obstruction charges for basically behavior in the performance of her official state duties. Because of the delicate nature of our federalist system —
— a delicate balance between federal and state power — federal prosecutors are often pretty loath to do this. And they usually only go after state officials for blatant corruption. Remember good old former Illinois Governor Rod Blagojevich and his pay-to-play scandal out in Illinois, where people basically had to bribe him to get posts in his administration? He faced a litany of federal charges. That's the typical type of case like this. Second, this is a judge — not a politician, not a governor, not a legislator. And cases against judges are exceedingly rare.

Mathieu: I'm assuming the judge will not end up on Celebrity Apprentice like Blagojevich. But have there been any other cases like this against judges recently?

Medwed: Yeah, a couple [prominent examples] come to mind. About 10 years ago, [federal Judge Samuel Kent] out in Galveston, Texas was accused with a series of sex offenses related to how he treated his staff. A judicial committee was investigating him internally for misconduct. He apparently lied to that committee [and] later plead guilty to obstruction of justice based on those lies. Also, about 25 years ago, another federal judge out west named Robert Aguilar heard about a looming FBI investigation into the business dealings of a distant relative of his. He tipped off the relative, the FBI got wind of that [and] interrogated Judge Aguilar. Judge Aguilar lied to the FBI [and] was charged and convicted of, among other things, obstruction of justice. That case was later tossed out by the Supreme Court for complicated reasons, but taken together, Kent and Aguilar are good examples of obstruction cases against judges. And they are very far removed from the Shelly Joseph case.

Mathieu: Why did U.S. Attorney Andrew Lelling pursue charges against [Judge] Joseph? Attorney General Maura Healey called it “a radical and politically motivated attack on our state and the independence of our courts.” It's pretty strong language. Do you agree with it?

Medwed: I tend to agree with our attorney general here. Just because you can charge someone with a crime, doesn't mean you should. Prosecutors need to exercise their discretion to balance the pros and cons. And here, the cons are enormous. This feels like a warning shot being leveled against state court judges across the country — you better toe the line and adhere to ICE, or else you're going to face the federal music.

Mathieu: Clearly, this warning shot has not been received well around here. Enter the lawsuit that I mentioned — a federal lawsuit. It's backed by Suffolk DA Rachel Rollins, among others, as they try to stop ICE from making courthouse arrests. Does this have any chance anywhere?

Medwed: Well, it's a very interesting lawsuit. On the one hand, I'll admit, I think the odds are stacked against it. After all, we have the Supremacy Clause. That means that the federal law is the supreme law of the land. And it's going to be hard to argue — in federal court, no less — that federal immigration authorities effectively lack jurisdiction to make civil arrests in Massachusetts state courthouse. But on the other hand, the legal theory here is pretty compelling. The idea is that the threat of ICE being present in a courthouse may be enough to interrupt Massachusetts state court proceedings because certain victims and defendants aren't going to appear — it's going to gum up the works. And it also stands in contrast to certain long-standing common law principles against making civil arrests in courthouses. Also, let's add the overlay that the federal judiciary doesn't love President Trump. Our local judges here in the District of Massachusetts could possibly look kindly on this lawsuit. So we better stay tuned.