President Donald Trump has kept his tax returns private, breaking with tradition that candidates for president release them. But now, a subpoena to an accounting firm with the taxes could lead to them being released to New York prosecutors.

Albany Law Professor Vin Bonventre says the question over whether the president can be prosecuted in a criminal case is unclear.    

"Anybody tells you they're certain one way or the other is just speaking nonsense. There isn't anything in the constitution that suggests one way or other the president can be prosecuted or can't be prosecuted while in office," Bonventre said.

In similar cases, like when the court forced President Nixon to turn over recorded conversations in the Oval Office, those help provide a guide.  

"Can we really allow all 50 states to be interfering with the president doing his duties? That may be too much," Bonventre said.

Governor Cuomo this month suggested President Trump changed his residency from New York to Florida to avoid having his taxes released.  

"My hypothesis is Mr. Trump changed his residence for legal purposes," Cuomo said.  

But Bonventre says that's unlikely.  

"That shouldn't have anything to do with it. If one person commits a crime in one state and then goes to another state, that doesn't immunize them from prosecution," Bonventre said.

The president's legal team has said he is immune from prosecution while he is in office.