Trump issued a tweet earlier this morning insinuating that he had taped a conversation between Jim Comey and him when Comey was in the White House for dinner on January 27, 2017. Also insinuated in the tweet was: (a) Comey did not know his oral communication had been intercepted and recorded; and (b) Trump would use the contents of the tape to force Comey not to discuss his dinner conversation with Trump.
The White House is in Washington, D.C., of course, so the federal wiretapping statute provides the framework to analyze the legality of Trump taping Comey’s conversation. No state wiretapping statute would be applicable. So, what does the federal wiretapping statute say?
The federal wiretapping statute is 18 USC Section 2511. It makes it a federal crime to intercept an oral communication, but then provides, at subsection (d):
"It shall not be unlawful under this chapter for a person not acting under color of law to intercept a[n] ... oral .... communication where such person is a party to the communication or where one of the parties to the communication has given prior consent to such interception unless such communication is intercepted for the purpose of committing any criminal or tortious act in violation of the Constitution or laws of the United States or of any State."
Under the facts here: (1) Trump was not acting under color of law, so subsection (d) applies; and (2) Trump was a party to the conversation where Comey’s oral communication was intercepted. So, in order for Trump to have run afoul of the statute, he would have had to have intercepted the communication “for the purpose of committing [a crime or a tort].”
So, if Trump recorded Comey's 1/27/2017 dinner conversation without Comey's knowledge, and did so for the purpose of blackmailing or extorting Comey to keep him from leaking to the press, then Trump violated 18 USC 2511. That is because extortion by a federal official is a crime punishable by up to 3 years in the penitentiary. 18 USC Section 872. So, to tape Comey for the purposes of accomplishing an act that violates 18 USC Section 872 would violate 18 USC 2511.
Trump's tweet this morning hinting that such a tape exists at least constitutes probable cause for federal prosecutors to use the already-convened grand jury investigating the Russian connection to issue a subpoena for the tape.