(CNN) A top prosecutor in the Roger Stone criminal case told CNN on Tuesday that his protest resignation from the Justice Department was "the most painful professional experience" of his career.

The comments from Jonathan Kravis , who made an exit from the case just before Stone's sentencing , provide a rare glimpse into the high-profile departure that prompted a weeks-long backlash toward Attorney General William Barr's leadership at the Department of Justice and President Donald Trump 's perceived political influence in criminal convictions against his friends and associates. Kravis and the other federal prosecutors who quit the Stone case have not spoken publicly about their departures.

"I don't really view this as a political statement," Kravis said of taking a new job this month with the DC Attorney General -- essentially the state-level prosecutor in Washington -- at a time when the office is working to increase its focus on public corruption. "I believe deeply in the importance of investigating and prosecuting public corruption cases."

Kravis refused to say much else about the Stone case and his departure, and instead explained that his new job will largely focus on building out the city's ability to pursue criminal cases against public officials, campaign finance investigations and other local issues. That could potentially include Trump.

The nation's capital has historically had little ability to investigate and prosecute because of the Justice Department's outsized jurisdiction to bring criminal cases in the city, especially compared to states. But DC Attorney General Karl Racine's office has aggressively pursued Trump through civil cases, such as by suing and attempting to get documents from the Trump International Hotel in DC, and by suing the Trump inaugural committee and businesses for their spending at the hotel during the 2016 inauguration.

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