In his bestselling 2016 book on terrorism, "The Field of Fight," retired Lt. Gen. Michael Flynn described growing up "hell-bent on breaking rules for the adrenaline rush and hardwired just enough to not care about the consequences."
On Friday, it became clear that Flynn broke one rule too many.
Flynn abruptly pleaded guilty in federal court to one count of "willfully and knowingly" making "false, fictitious and fraudulent statements" to the FBI about his communications with Russia's ambassador last December, after Donald Trump had named Flynn his national security advisor.
As part of a plea agreement, Flynn also said he was cooperating with the investigation led by special counsel Robert S. Mueller III into whether anyone in Trump's orbit helped Moscow's efforts to meddle in last year's presidential campaign, suggesting higher-ups in the White House may face legal jeopardy.
The guilty plea was the latest dip in Flynn's roller-coaster career — an up-and-coming battlefield intelligence officer in Iraq and Afghanistan, promoted to a three-star Army general, named to head the Defense Intelligence Agency and then fired in 2014 for what the White House said was mismanagement.
His tenure as President Trump's national security advisor set a dubious record: He was ousted after only 24 days for misleading Vice President Pence and others about his discussions with Sergey Kislyak, then Russia's ambassador to Washington, about easing U.S. sanctions on Russia.
"It's a sad thing," retired Army Gen. Barry McCaffrey said Friday. "We owe Flynn a lot, and he went over the line."
Flynn's hard-charging nature was core to his persona. In Afghanistan, his commanding officer once praised him as someone who "just busts down walls" to get the job done.
But that determination sometimes clouded his ability to make considered decisions.
"If you're not someone blessed with the gift of good judgment, you end up in the situation he's in," said Derek Chollet, a former senior Pentagon official in the Obama administration.
Flynn was always pushing the limits as a kid in a working-class family in Middletown, R.I., whether surfing during hurricanes, jumping off bridges or playing sports.
"He was a lineman on our football team," said Thomas Heaney, a childhood friend. "He was probably 155 pounds, and he would play guys 80 to 100 pounds heavier than him."
Flynn wrote in his book that he was something of a hard case, participating in "some serious and unlawful activity" that led to his arrest and a "very unpleasant night" in a state reformatory for boys. His record was expunged after a year of supervised probation, he wrote.
He straightened out, dated a high school classmate he eventually would marry and scored an Army ROTC scholarship at the University of Rhode Island. It was a logical step for the son of a man who served more than two decades in the Army. (One brother, Charlie, still serves as a general.)
But Flynn also swam against political currents by enlisting in the Army soon after the Vietnam War, which had sparked protests across the country.
"We didn't do a lot of big formations," said Heaney, who joined ROTC with Flynn. "We didn't do a lot of things as a group out on the campus just to not provoke any kind of negative feelings."
Over the years, Flynn rose to prominence as an Army intelligence officer. A former commander called him "tireless, focused, serious, and thought about how he went about connecting dots."
In Iraq, Flynn teamed up with Gen. Stanley McChrystal and followed him to Afghanistan as a senior aide. McChrystal envisioned a more nimble military force that prioritized gathering intelligence about insurgents in nighttime raids, then swiftly sifting the information to launch more attacks.
"It's said that Gen. McChrystal built a killing and capturing machine," said the former commander, who spoke on condition of anonymity because of the legal case. "This was the intelligence component of that machine."
Flynn's contrary nature was clear in the Pentagon. He contributed to a disparaging 2010 report saying the "vast intelligence apparatus is unable to answer fundamental questions about the environment in which U.S. and allied forces operate and the people they seek to persuade."
Flynn flamed out in his next assignment, however, after President Obama named him head of the Pentagon's spying arm, the Defense Intelligence Agency, in July 2012.
Critics in the Pentagon, the intelligence community and on Capitol Hill soon described Flynn as out of his depth running the 17,000-person agency. Some said he advanced unreliable theories.
"His penchant for inventing his own facts and asking people to chase down evidence to support them — the so-called 'Flynn facts' — is deeply disturbing for an intelligence officer," said Rep. Adam Schiff (D-Burbank), the top Democrat on the House Intelligence Committee.
Flynn was ousted in August 2014 after clashing with James Clapper, who was Director of National Intelligence, and other officials. Flynn later blamed the White House, saying Obama had failed to reckon with the growing strength of Islamist terrorists.
"I was fired as the director of the Defense Intelligence Agency after telling a congressional committee that we were not as safe as we had been a few years back," Flynn wrote in his book.
He scorned the idea of cashing in on his military experience and contacts, like other former government officials who parlayed their public service into private-sector profit.
"Flynn used to run around bragging that his stars weren't for sale," according to one former intelligence official.
When Trump announced his presidential campaign in 2015, one of his aides, Sam Nunberg, believed the newly declared candidate would take a shine to Flynn and helped arrange a meeting.
"He had made the talk-radio rounds. He had criticized the Obama administration," Nunberg recalled.
The bond gelled at the Republican National Convention, when Flynn delivered an angry speech denouncing Democratic nominee Hillary Clinton and led the crowd in chants of "Lock her up."
At the time, Trump was under attack from veterans in the U.S. national security community, who worried about Trump's lack of any military or government experience and his unconventional policies. Flynn's 33 years in the military and battlefield experience helped deflect criticism.
A former Trump campaign policy advisor said Flynn was so close to Trump during the fall campaign that he rarely interacted with other members of the national security team.
"Both shared a similar worldview, and I believe were driven at least in part by sheer condescension from people like Barack Obama, Hillary Clinton and Jeb Bush," the former advisor said.
Like Trump, Flynn warned about the dangers of "political correctness" in America and stoked fears of "radical Islam" at home and abroad.
But Flynn built more than a right-wing political profile last year. He also expanded his business, the Flynn Intel Group, and his financial interests weren't always properly disclosed.
His first financial disclosure form, filed in January, detailed more than $1.3 million in income last year. Some payments came from well-known companies like Adobe Systems. Others were from groups like ACT for America, which has been accused of Islamophobia.
His second report, filed in March, revealed payments from a Russian air cargo company and a Russian cybersecurity company, both for speeches he delivered in Washington.
And it wasn't until the third report, filed in August and revealing at least $1.8 million in income, that Flynn mentioned his work as a consultant for ACU Strategic Partners, a company seeking to develop nuclear power plants in the Middle East. An earlier trip to the region wasn't disclosed on his application for a security clearance, according to Democrats on the House Oversight Committee.
There was another problem with Flynn's private sector work.
Before the election, Flynn signed a contract with a Turkish-owned company to help undermine Fethullah Gulen, a political enemy of Turkish President Recep Tayyip Erdoğan who lives in Pennsylvania. Flynn didn't register as a foreign agent until March, when he detailed $530,000 in payments.
Former CIA Director R. James Woolsey Jr., who attended one of Flynn's meetings with Turkish officials, said they discussed forcibly removing Gulen from the country, a move Woolsey feared would be illegal.
Flynn's work with Trump could have ended with the election. New Jersey Gov. Chris Christie, who was running the future president's transition team, was "not a fan" of the former general, according to sources with knowledge of the relationship, and didn't include him on a list of potential national security advisors.
Binders of plans and recommended appointments were delivered to Trump Tower in New York on election day in case Trump won an unlikely victory. But once Trump did, Christie was deposed, and his ideas — and the binders — were discarded.
Trump quickly named Flynn his national security advisor, a position of immense influence in the White House.
Flynn was almost immediately engulfed in controversy.
U.S. intelligence monitoring the Russian ambassador picked up Flynn's conversations with the diplomat. Sally Yates, a former acting attorney general, later testified to Congress that she warned White House lawyers in January that Flynn "was compromised" and "could be blackmailed" by Russians.
After he was pushed out, Flynn returned to his Rhode Island hometown, passing the summer days surfing and hanging out with family. He registered a new consulting firm, Resilient Patriot, in Virginia, but it's unclear what work it did.
His siblings opened a legal defense fund on Flynn's behalf, saying he needed help despite the $1.8 million in income he reported in August
"The defense fund is still open and we're still getting a lot of support," said Joe Flynn, the defendant's younger brother. "He's not a man of means that can support this type of financial burden."
10:29 a.m.: This article was updated with Flynn plea agreement and his brother's defense fund.