Former federal prosecutor says common Mueller criticism is that he was too hard on Flynn

Former federal prosecutor Joesph Moreno on Tuesday said that a major, public criticism of special counsel Robert MuellerRobert (Bob) Swan MuellerThis week: Mueller dominates chaotic week on Capitol Hill Top Republican considered Mueller subpoena to box in Democrats Kamala Harris says her Justice Dept would have 'no choice' but to prosecute Trump for obstruction MORE is how hard he came down on President TrumpDonald John Trump5 things to know about Boris Johnson Conservatives erupt in outrage against budget deal Trump says Omar will help him win Minnesota MORE's former national security adviser, Michael Flynn.

Flynn pleaded guilty last year to lying to the FBI about his contacts with Russian Ambassador Sergey Kislyak. 

He also agreed to cooperate with Mueller's probe, becoming the first high-ranking Trump adviser to do so.

"If there's one criticism to be had of the special counsel, just to be totally objective about this, there are people that credibly say it seems like he came down really hard on General Flynn, possibly unnecessarily," Moreno told Hill.TV's Buck Sexton and Krystal Ball. 

Moreno's comments come as Mueller is set to release memos on Flynn, along with Trump's former personal lawyer Michael Cohen and former campaign chairman Paul ManafortPaul John ManafortHow Mueller deputy Andrew Weissmann's offer to an oligarch could boomerang on DOJ Ukrainian officials and Giuliani are sharing back-channel campaign information: report Key numbers to know for Mueller's testimony MORE.

The memos are expected to give more insight into the inner workings of the federal investigation into connections between the Trump campaign and Russian interference in the 2016 presidential election. 

CNN reported on Tuesday that the memo on Flynn is expected to detail the crimes Flynn committed that led to his guilty plea and how he has aided the Russia probe this year. 

"So will we find more details about what exactly he's alleged to have lied about and what he cooperated about? Perhaps. It's still on people's minds," he continued.

Officials have accused Flynn of attempting to create a back channel for communications between Russia and Trump.

"Many people say there's nothing wrong with him having those backchannel communications. He was the incoming national security adviser," Moreno said. "Of course not being truthful to the FBI is what he's being charged with." 

— Julia Manchester