Caroline Polisi is a federal and white collar criminal defense attorney at Pierce Bainbridge in New York City and an adjunct Lecturer in Law at Columbia Law School. She frequently appears on CNN as a legal analyst. Follow her on Twitter: @CarolinePolisi. The views expressed in this commentary are her own. Read more opinion on CNN.

(CNN) The arrest on Thursday of two associates of Rudy Giuliani on campaign finance charges has people asking the obvious question: what does this mean for the Trump impeachment investigation?

Most gallingly, the indictment alleges that Parnas and Fruman sought help from a sitting congressman to remove or recall the US ambassador to Ukraine, Marie Yovanovitch. While neither the indictment nor the US attorney who announced it, Geoffrey Berman, mentioned President Trump or Giuliani, his personal lawyer, it's hard to resist putting two and two together.

Yovanovitch was reportedly removed after complaints from Giuliani and others that she was thwarting his efforts to coax the Ukrainian government to investigate former Vice President Joe Biden and his son Hunter, according to the Wall Street Journal.

We are also learning more details daily about the now-infamous July phone call between Trump and Ukrainian President Volodymyr Zelensky, in which Trump asked for a "favor" in the form of an investigation into his political rival, now the basis for a whistleblower complaint

Read More