For those of us who have tried for decades to convince state and federal lawmakers and judges across the nation the value of allowing journalists to protect the identities of confidential sources, the opinion issued Tuesday by New York’s Court of Appeals could not have been more heartening.

There is “no principle more fundamental or well-established than the right of a reporter to refuse to divulge a confidential source,” the court ruled.

Amen.

The 4-3 decision means Fox News reporter Jana Winter will not have to travel to Colorado to testify in the murder trial of James Holmes, who is accused of carrying out a mass shooting in a movie theater in Aurora, Colo.

Among other things, Winter’s welcome reprieve illustrates the haphazard, irrational state of the reporter’s privilege in state and federal courts. Without launching into a complicated dissection of the differences between the level of protection for reporters and sources in the various states and federal circuits, suffice it to say that had she been working for the Denver Post when she obtained confidential source material while covering the story in Colorado, Winter would be looking at jail.

This case illustrates why I (and my fellow faculty members who teach media law at Philip Merrill College of Journalism) repeatedly warn our journalism students that they will have to pay attention to widely differing state laws when they leave Maryland to become working journalists.

Winter worked for a New York-based company in a New York newsroom, and her lawyers successfully persuaded a New York court that she should be protected from revealing her sources by New York’s shield law.

Here’s a mini-tutorial on how courts usually handle subpoenas for out-of-state reporters: Winter is a New York-based reporter for Fox News Channel. She was sent to Colorado to cover the Aurora shooting. A confidential source(s) gave her information about a notebook Holmes had sent to a University of Colorado psychiatrist. That information was confidential, and Holmes’ attorneys asked the Colorado trial court to order the reporter to identify her source(s). The court did so.

But Winter had returned to New York, so the Colorado court had to ask the New York courts to recognize the subpoena and order Winter to return to Colorado to testify. Today, New York’s Appeals Court gave a resounding thumbs-down to Colorado’s efforts to haul Winter back to Colorado to testify.

“We therefore conclude that an order from a New York court directing a reporter to appear in another state where, as here, there is a substantial likelihood that she will be compelled to identify sources who have been promised confidentiality would offend our strong public policy — a common law, statutory and constitutional tradition that has played a significant role in this State becoming the media capital of the country if not the world,” Judge Victoria A. Graffeo wrote in the majority opinion.

Graffeo’s summary of New York’s attitude toward press freedom is the reason that for decades advocates across the country who have tried to persuade lawmakers to pass a shield law have used the New York shield statute as a model.

Now, if only New York Times reporter and book author Jim Risen worked out of New York and had been subpoenaed to appear in a state, not federal, court. But that’s a another issue for another day . . . . .