In an interview, Mr. Taylor was careful not to confirm the scope of his involvement with the Ghosn escape or what he might have been paid, if anything. But he said Mr. Ghosn’s case resonated with him because of his own bitter experience with the U.S. judicial system that resulted in prison time.

“I learned about Carlos Ghosn’s plight, and felt very much like him, in the sense that we were both held hostage in an unfair legal system,” Mr. Taylor said.

The escape plan just before New Year’s Day involved months of preparation and a nail-biting episode where the fleeing executive was smuggled through Japanese airport security packed inside an audio-equipment case with breathing holes drilled into the bottom, details The Wall Street Journal first reported earlier this month.

Mr. Ghosn has claimed since escaping that he had no chance of a fair trial in Japan, and said he was particularly angry about being banned from having contact with his wife as part of his bail conditions. Japanese authorities have defended their system, saying he would have had a fair trial had he stayed. They said Mr. Ghosn was kept from his wife to prevent witness tampering.

The 59-year-old Mr. Taylor has bulging biceps, gray hair and a wide smile. He rarely drinks alcohol, but often has a wad of chewing tobacco in his cheek.

He remains emotional about his own prison stint in the U.S., after pleading guilty to two charges stemming from a federal bid-rigging probe. He has told friends he had agreed to the plea deal only because he had been held in what he described as a brutal Utah county jail for 14 months awaiting trial. Robert Lund, a Utah federal prosecutor involved in Mr. Taylor’s case, said “he definitely committed the crime,” noting that all of his fellow defendants also pleaded guilty.

So far, Mr. Taylor’s exact role in the Ghosn caper isn’t clear. Passport information reviewed by the Journal shows he and a longtime associate were on the plane that took Mr. Ghosn to Turkey, and newly released video footage shows them at an Istanbul airport after the plane landed.

Japanese authorities have said two foreign men accompanied Mr. Ghosn to an Osaka hotel, then wheeled the box through the lobby of the Osaka airport. The authorities said they believe the two men to be Mr. Taylor and the associate.

Tokyo prosecutors had charged Mr. Ghosn, the former chairman of Nissan Motor Co., with financial crimes, including allegedly causing the company to fail to report ¥9.2 billion ($84 million) in deferred compensation over eight years of its financial statements. Mr. Ghosn has denied the charges. After his escape, Japan issued a red notice through Interpol, the international police organization, saying Mr. Ghosn is wanted for extradition, and he has forfeited the nearly $14 million in bail money he paid. Mr. Taylor isn’t charged with any offense related to Mr. Ghosn’s escape, in Japan or elsewhere.

Mr. Taylor was brought in to help rescue New York Times reporter David Rohde from Taliban captivity in Afghanistan. He also worked with the U.S. government to rescue children who had been kidnapped overseas, according to a memo produced by his lawyers in his criminal case.

“The guy was clearly a black-ops type,” said a law-enforcement official who knows him. “He did the kind of things that law enforcement couldn’t do.”

Born in the New York City borough of Staten Island, Mr. Taylor was raised partly on a military base outside Boston. He joined the Army Special Forces after high school despite his stepfather, who served in the Army, telling him at the time he didn’t believe somebody so young could do the rigorous training, he has told friends.

He met his Lebanese-born wife during deployment in that country in the early 1980s and he learned some Arabic. The Taylors, who have three adult children, live outside Boston but own a residence in Beirut.

In 1994, he founded a small Boston-based security firm, American International Security Corp., now defunct, that did local work in the Boston area and also served as a vehicle for overseas assignments, including a rescue of a woman and her children from Syria, court records show.

In Boston, Mr. Taylor kept company with some infamous characters and had some run-ins with the law.

Mr. Taylor was friendly, for instance, with John J. Connolly Jr., a now-disgraced former FBI agent who secretly aided mobster Whitey Bulger and is serving time for his role in a mob murder. Mr. Taylor had no links to Mr. Bulger. But after he left the FBI and before his 1999 indictment, Mr. Connolly helped drum up business for Mr. Taylor’s security company, according to people familiar with the matter.

Mr. Taylor pleaded guilty to misdemeanor charges of breaking and entering and making a false police report in the 1990s, in a case related to planting marijuana in the car of a client’s estranged wife. In the early 2000s he was caught up in a federal investigation into a trucking-related shakedown that sent a Boston Teamsters union chief to prison. Mr. Taylor agreed to cooperate with investigators and was never charged.

Another close associate was the late Duane “Dewey” Clarridge, a legendary CIA official who was indicted in 1991 for his role in the Iran-Contra affair but pardoned by President George H.W. Bush. He and Mr. Taylor later worked on several projects in Afghanistan, including the Rohde rescue effort, and talked frequently, according to people familiar with them.

While a high-school football player, Mr. Taylor showed his fiercely competitive nature, according to a teammate, Joe Morris, who later won a Super Bowl ring playing for the New York Giants. “Mike would humiliate the guys he played, just beat them into the ground,” Mr. Morris recalls.

A decade ago, Mr. Taylor served three years as a football coach at a Boston-area private school, Lawrence Academy. Mr. Taylor brought in a half-dozen ex-NFL players or coaches to help with training and conditioning. The teams he fielded had multiple players who went on to Division I college teams, including several who weighed more than 300 pounds.

One year his team was so feared that a rival school forfeited rather than risk its players’ safety—an event that made national news.

After Mr. Taylor left as coach in 2011, the team was stripped of two titles it won when he was there, which the school said was partly due to violation of league rules related to financial aid and summer training. Mr. Taylor said many of the star players were already at the school when he arrived, financial aid was handled by school administrators, and he was never told why the team was disciplined.

In the mid-2000s, Mr. Taylor’s company was a security contractor working for the U.S. government in Iraq, helping ensure rebuilding supplies were safely delivered. Mr. Taylor “always executed in a very professional manner,” said Jack Holly, a retired Marine colonel who ran the Pentagon’s vast civilian logistics operation in Iraq.

When he heard Mr. Ghosn’s escape from Japan involved Lebanon, “I said, I wouldn’t be surprised if it was Mike,” Col. Holly recalls. “He’s the type of guy who could do something like that.” Mr. Taylor’s 2015 sentencing memo quotes a grateful letter from the mother of one girl taken by her father to Lebanon who Mr. Taylor’s firm brought back in 1997 after a four-year effort.

“If one of my relatives was being held, I’d call Mike,” said Terry Sullivan, an ex-Navy SEAL who worked with Mr. Taylor on the 2009 operation to help rescue the Times reporter, Mr. Rohde, from the Taliban. Mr. Rohde didn’t respond to requests to comment.

Mr. Taylor was indicted in 2012 on charges that he fraudulently won $54 million in Pentagon contracts in Afghanistan by bribing a Pentagon official to obtain confidential bidding information, then allegedly bribed an FBI agent to try to derail the investigation.

He denied the allegations, but a federal judge decided he was a flight risk due in part to his overseas security contacts and Lebanon residency permit. He was confined to a county jail for more than 14 months while awaiting trial.

Mr. Taylor remains incensed that prosecutors at one point argued he shouldn’t get bail because he had a history of bribing overseas officials, citing a press article about alleged bribes paid to the Taliban in the course of his work trying to rescue Mr. Rohde.

“I’m working to save the life of an American citizen, a journalist, and they used that against me,” he said.

Mr. Taylor eventually pleaded guilty to two counts, down from more than 50 originally, and served a total of about 19 months. His security company closed down during this period and after emerging from prison in 2015 he started a small vitamin-water business.

He also wrote a memo about his legal experience, shared with a few people.

He wrote that he had been denied bail on “totally false claims” by prosecutors, and had pleaded guilty only to avoid a longer stay in the “brutal” jail, saying “he could not exercise, go outdoors or even see daylight. He could only meet his family through plexiglass or on a video screen, while shackled at the waist, feet and hands.”

Mr. Lund, the prosecutor involved in the case, said Mr. Taylor’s Green Beret career was “super impressive.” As for Mr. Taylor’s complaints about his incarceration, Mr. Lund said he wasn’t treated any more harshly than others. “It was just normal county jail time. Being in jail is an unpleasant experience.”

Write to Mark Maremont at mark.maremont@wsj.com and Nick Kostov at Nick.Kostov@wsj.com