John McAfee is no stranger to a striking image. In 1987, as he began to dominate the brave new world of anti-virus software, the tech founder advertised his namesake company with a moody black-and-white self-portrait in which he held a stethoscope to a sickly computer. In 2017, he claimed he would “eat his own d**k on national television” if Bitcoin’s trading value didn’t reach $500,000.

McAfee has zigzagged from Silicon Valley darling to a “person of interest” in a murder case; from yoga guru to gun-toting womanizer; from crypto-currency evangelist to Libertarian presidential challenger. His Instagram account appears to be run by a hyperactive 12-year-old boy—McAfee’s face superimposed onto the Terminator; wacky outfits and conspiracy theories; wraparound shades and pump-action shotguns and a particularly itchy-looking nose. In a 2012 profile with Wired magazine, the man played Russian roulette with a Smith & Wesson in front of his interviewer; last year he launched a “meme” crypto-currency called WHACKD, marketed with the mantra “Epstein Didn’t Kill Himself.” For a self-declared fugitive, McAfee is not afraid of a little attention seeking.

McAfee has zigzagged from Silicon Valley darling to a “person of interest” in a murder case.

As he languishes in a Spanish prison cell, the 75-year-old multi-millionaire continues to send out round-the-clock dispatches via Twitter. (“Don’t ask how, just appreciate the mystery,” McAfee’s wife, whose whereabouts are unknown, tweeted last week.) This is the latest twist in the McAfee fever dream—a chapter that began on October 3, when the tech tycoon was arrested boarding a flight from Barcelona to Istanbul.

McAfee stands accused by the U.S. Justice Department of failing to file tax returns from 2014 to 2018—a period in which, according to a June indictment in Tennessee, he hoarded millions of dollars from “promoting cryptocurrencies, consulting work, speaking engagements, and selling the rights to his life story for a documentary.”

McAfee has one million followers on Twitter, his prison portal to the outside world.

A separate S.E.C. complaint claims McAfee made more than $23 million between 2017 and 2018 by shilling dubious “initial coin offerings” to his hundreds of thousands of Twitter followers—without declaring that he stood to benefit from their sale and was being paid to puff them up. If found guilty, McAfee could spend decades in federal prison. His extradition to the U.S. is pending.

Still, the old boy seems in good spirits. His Twitter output is a combination of prison-yard stand-up (“I am surrounded by murderers, muggers and thieves. Not as bad as our government of course.”); state-of-the-nation almost-haikus (“What remains in America / is the last landscape / of a disappearing world.”); and ominous tone shifts (“The food is good. All is well. Know that if I hang myself, a la Epstein, it will be no fault of mine.”)

It’s hard to know whose fingers are tapping the keys—it seems unlikely that even a proclaimed hacker-savant such as McAfee could secure a 24-hour smartphone in a Spanish prison. But a glowing tweet in praise of his wife, Janice (“She has been my inspiration, my muse, my friend, my confidante and my lover”), might furnish a clue.

“The food is good. All is well. Know that if I hang myself, a la Epstein, it will be no fault of mine.”

McAfee may well be in his element. “I gravitate to the world’s outcasts,” he once explained in an e-mail to friends. “Prostitutes, thieves, the handicapped.”

After losing the majority of his fortune in the financial crash of 2008, McAfee (who had resigned from the company bearing his name 14 years earlier) gave up his bougie yogi lifestyle and decamped to a town in Belize called Orange Walk—a swampy, poverty-stricken area covered in rain forest and studded with Mayan ruins. McAfee slipped into the role of a goateed, Oakley’d Colonel Kurtz. He employed a devoted troop of heavily armed ex-cons, hallucinated prying eyes all about him, and cavorted with a succession of young girlfriends he’d pick up at a local watering hole called Lover’s Bar (one of whom tried to shoot him with his revolver while he slept).

In 2012, Gregory Faull, a 52-year-old American expat neighbor of McAfee’s, was found dead with a gunshot wound to the head. McAfee, who was said to have clashed with Faull over the software mogul’s security detail and guard dogs, was named as a “person of interest.” McAfee reportedly buried himself in the sand to hide, before commandeering a boat to Guatemala, where the local authorities tried unsuccessfully to deport him back to Belize. (He denied any involvement in the murder.)

Last year, Faull’s family won a wrongful-death suit against McAfee in a court in Florida, where McAfee was ordered to pay more than $25 million. (He has not been charged with any crimes in Belize.)

McAfee cavorted with a succession of young girlfriends, one of whom later tried to shoot him with his revolver while he slept.

Since leaving his rain-forest encampment, McAfee has lived on the lam—existing “on the edge,” according to his Instagram captions, on board a boat built for “a drug lord who wanted it bulletproof.” In 2015 he was arrested in Tennessee for driving under the influence and possession of a handgun.

In 2016, he sought the presidential nomination of the Libertarian Party, running a prescient campaign around cyber-threats and the misuse of personal data. “I perceive an enormous danger facing America.… And no one is listening,” he said in a campaign video; he lost to former governor of New Mexico Gary Johnson. Around that time, McAfee began to transform himself into the P. T. Barnum of crypto-currency—promoting obscure financial instruments to his acolytes.

In a simpler time: McAfee and his wife, Janice Dyson, lived aboard a yacht after leaving his compound, in Belize.

In 2019, McAfee was arrested by police in the Dominican Republic for entering the country on a yacht carrying “high-caliber weapons, ammunition and military-style gear.” But mostly he just seems to have been having a perfectly jolly time.

Well, the party’s over now. In the torrent of tweets since his Spanish arrest, McAfee has framed the tax-evasion charges as part of a wider conspiracy. “I speak out against corruption in the FBI, the CIA, and most other government agencies. That is my only real crime,” he tweeted on October 10. In a ripple of cosmic irony, in October McAfee’s former company had its second I.P.O. since its founding, in 1987, raising $740 million.

McAfee the man, however, has resigned himself to the simpler pleasures of incarceration—new pals, knife fights, and navel-gazing. “I am content in here. I have friends,” he tweeted on October 15, and then two days later: “My cell mate is a Pakistani Muslim—a drug dealer. He said we are in prison because God is angry with us. That certainly explains much of my life.”

Joseph Bullmore is a Writer at Large for Air Mail