Beyond the contrast in circumstances and timing,there are undeniable differences between the two men,rooted in their respective ages,experiences,management styles and prosecutorial philosophies,that have shaped their divergent charging decisions.

“His disposition,compared to Mueller,seems very different – he’s working against the clock;Mueller moved a lot more slowly,” said Goodman,who is also a co-founder of Just Security,an online publication that has closely monitored the Trump investigations.

Trump and congressional Republicans have accused Smith,without evidence,of pursuing a politically motivated investigation intended to destroy Trump’s chances of retaking the White House,including by leaking details of the case. But department officials have said Smith is committed to conducting a fair investigation,and he has defended his own lawyers against attacks from the Trump team,who accuse them of using unethical tactics.

The former president has taken to calling Smith “deranged”,and some of his supporters have threatened the special counsel,his family and his team – prompting the US Marshals to spend $US1.9 million ($2.9 million) to provide protection for those who have been targeted,according to federal expense reports that cover the first four months of his tenure. Smith was flanked by a three-person security detail inside his own building when he delivered remarks to reporters on Tuesday.

Mueller was an established and trusted national figure when he was appointed special counsel,unlike Smith,who was virtually unknown outside the department and drew a mixed record during his tenure. Mueller had already solidified a reputation as the most important FBI director since J. Edgar Hoover,after protecting and reshaping the bureau at a time when some were calling for breaking it up following the intelligence failures that preceded the September 11,2001,terrorist attacks.

But there was,at times,a gap between the perception of Mueller and his ability to execute a difficult job under fire. Already in his mid-70s,he struck many of those who worked with him as a notably diminished figure who,in testifying before Congress at the end of the investigation,was not entirely in command of the facts of his complex investigation.

By comparison,Smith is someone who rose to the upper echelons of the Justice Department but is not well known outside law enforcement circles. At 54,Smith,a lifelong prosecutor,is leading the investigation at the height of his career,not at the end of it.

Smith is fresh off a stint as a war crimes prosecutor in The Hague and took over two investigations that were already well down the road. Smith sees himself as a ground-level prosecutor paid to make a series of fast decisions. He is determined to do everything he can to quickly strengthen a case (or end it) by squeezing witnesses and using prosecutorial tools,such as summoning potential targets of prosecution before a grand jury to emphasise the seriousness of his inquiries,people close to him have said.

When Smith took over as chief of the Justice Department’s public integrity unit in 2010,the unit was reeling from the collapse of a criminal case against former Republican senator Ted Stevens. In his first few months on the job,he closed several prominent investigations into members of Congress without charges.

At the time,Smith brushed off the suggestion that he had lost his nerve. “If I were the sort of person who could be cowed,” he said,“I would find another line of work.”

Among his more notable corruption cases was a conviction of Robert McDonnell,the Republican former governor of Virginia,that was later overturned by the Supreme Court,and a conviction of former representative Rick Renzi,whom Trump pardoned during his final hours as president.

Smith appears to be somewhat more involved than Mueller in the granular details of his investigations. Even so,he seldom sits in personally on witness interviews – and spoke only sparingly during two meetings with Trump’s defence lawyers,delegating the discussions to subordinates,according to people familiar with the situation.

Smith’s stony style,intentional or not,has the effect of sowing considerable unease across a conference table or courtroom.

James Trusty,who quit the former president’s defence team a day after meeting Smith’s team in June,worked for years with Smith as a senior criminal prosecutor at Justice Department headquarters and told associates he was a “serious” adversary not to be underestimated. Other lawyers said Smith’s team had fed the sense of mystery by describing him in veiled or cryptic terms,with one calling him “the man behind the curtain”.

He has been more public-facing than Mueller in one critical respect – delivering short,sober statements to the news media after each grand jury indictment.

Mueller said little when faced with a barrage of falsehoods pushed publicly by Trump and his allies about him and his investigative team. But at a news conference after Trump was indicted in the documents case,Smith seemed to be speaking with an added purpose:to rebut claims that one of his prosecutors,Jay I. Bratt,had inappropriately pressured a defence lawyer representing one of Trump’s co-defendants,according to a person with knowledge of the situation.

“The prosecutors in my office are among the most talented and experienced in the Department of Justice,” he said. “They have investigated this case hewing to the highest ethical standards.”

During Trump’s arraignment in Miami in June,Smith sat in the gallery,closely watching the proceedings. Some in the courtroom suggested he stared at Trump for much of the hearing,sizing him up.

But that was not really the case. He listened intently to the lawyers on both sides,at times leaning in towards a colleague to make a whispered comment or ask a question.

This article originally appeared inThe New York Times.

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