“This is an extremely dangerous situation to allow the president to get in because he does not know and cannot know as much about the case as Bob Mueller and his fellow interrogators will know,” Napolitano said. “He might very well say things which would lead them to other areas of investigation like, are you telling us the truth?”

Napolitano said Mueller would subpoena Trump if he refused to sit down for an on the record meeting, but thinks it could backfire if Mueller isn’t careful.

“That’s also dangerous for Bob Mueller because he does not know what the president is going to say to the grand jury. Remember, grand jury meets in secret. The president’s lawyers cannot be there. Just the president as the witness will be there and Bob Mueller and his team interrogating him,” Napolitano said. “Prosecutors don’t like to put somebody on before a grand jury without knowing ahead of time what they’re going to say.

“[Trump] could go on for an hour in an answer if he wanted to,” Napolitano added.

Host Bill Hemmer played a clip of Harvard Professor Alan Dershowitz discussing the Mueller investigation and asked Napolitano if he agreed with Dershowitz.

“If the president were to be charged with obstruction or simply exercising his constitutional authority, firing Comey, telling Comey not to investigate Flynn, those are all within the president’s constitutional authority,” Dershowitz said. “The other place it may be going is toward collusion. Collusion is not a crime. I would think that the special prosecutor should limit himself to matters that are criminal, and thus far, I have not heard evidence to suggest that any crimes were committed in or near the oval office.”

Napolitano didn’t fully agree with Desrhowitz’s assessment but said if Trump had a “legitimate” reason for his actions then he did not obstruct justice.

“Obstruction of justice needs to be for a corrupt purpose. If it’s for a good purpose, like reallocating resources, and the president is the chief law enforcement officer of the land, it’s absolutely not criminal,” Napolitano said. “But if it’s for a corrupt purpose like protecting himself from the revelation of the truth, then that’s obstruction of justice.”