Manhattan DA Alvin Bragg criticizes Donald Trump book, says case against former president wasn't ready

Manhattan District Attorney Alvin Bragg responded for the first time since the release of a book Tuesday by former special assistant district attorney Mark Pomerantz, which accuses Bragg of making a mistake by failing to bring a criminal case against former President Donald Trump at the onset of his tenure.

"I bring hard cases when they are ready," Bragg said Tuesday in response to a question from ABC News. "Mark Pomerantz's case was not ready."

Bragg called Pomerantz's criticisms of the prosecutors in the district attorney's office "appalling," saying they're committed to keeping the public safety "from the suites to the streets."

The book, "People vs. Donald Trump: An Inside Account," was released Tuesday.

Bragg said he has not read the book, but he has seen televised interviews with Pomerantz in which he criticizes Bragg for declining to bring a criminal case over Trump's statements of financial condition.

A parallel civil case by New York Attorney General Letitia James alleged those statements were fraudulently completed to inflate Trump's net worth so he could obtain better loan terms.

Bragg said he remained concerned the book could undermine his ongoing investigation.

Bragg's office sent a letter in mid-January to both Simon & Schuster, the book's publisher, and Pomerantz expressing concern that the book could interfere with the ongoing investigation.

"Based on the pre-publication descriptions of his book and the benefit of current knowledge of the matter, but without access to the manuscript, this Office believes there is a meaningful risk that the publication will materially prejudice ongoing criminal investigations and related adjudicative proceedings," read the letter, a copy of which was obtained by ABC News.

A grand jury has started hearing evidence about Trump's role in hush payments to Stormy Daniels, sources have told ABC News.

Trump's former personal attorney, Michael Cohen, is expected to appear before that grand jury this week, sources told ABC News.