(CNN) When Donald Trump has a problem, Keith Schiller is often the solution.

Never was that clearer than earlier this year, when Trump -- nagged by questions about a series of baseless claims he made about his predecessor, Barack Obama -- leaned on Schiller to get the pestering press out of his meeting.

"Mr. President, any proof on the wiretapping?" yelled a reporter. "Mr. President, any proof at all?"

Enter the 6'4", 210-pound Schiller, a man who, after working for Trump for nearly two decades, knew his usually loquacious boss didn't want to talk.

"Please get out of the way," the former New York Police Department detective barked. "Thank you."

Schiller, whose official title is deputy assistant to the President and director of Oval Office operations, got in front of the reporters and quickly escorted them out of the room, playing the role of press handler.

The former police investigator has risen from a high school student who coaches doubted would amount to anything to Trump's muscle-for-hire to, arguably, the person Trump trusts most outside his own family. Schiller, who has an apartment near Trump's in Trump Tower, wears many hats in the White House: press wrangler, body man, private muscle and sounding board.

He regularly travels with Trump and his family, is seen in countless photos with the President and even serves as a top security adviser to Trump's aides. When Jared Kushner, Trump's son-in-law and top policy aide, traveled to Iraq with Marine General Joseph Dunford, the chairman of the US military's Joint Chiefs of Staff, Schiller was at his side for much of the trip.

Trust

Trump's management style, advisers say, has also long been collaborative, with the President regularly asking people close to him for their views, even if they have no expertise in the field. Schiller is often that person next to the President and regularly offers his thoughts, friends say. And in a White House filled with new hired hands and paid advisers, his relationship with Trump has something that only time could cement: Trust.

That trust is apparent to anyone who interacts with Trump and Schiller. In fact, former campaign aides described how many in Trump's orbit craved Schiller's approval, knowing that it would lead to Trump's backing.

"It mattered more to me what Keith Schiller thought of me than what the campaign manager thought," said a former top campaign aide. "Now I think it means more what Keith thinks of you than Reince (Trump's chief of staff) thinks of you."

The aide called him the "most underestimated person on Trump's team."

Schiller's rise has been far from meteoric -- the 58-year-old New York native has held an odd array of jobs on his path to Trump. Schiller's high school friends are now shocked that the guy who helped them sneak into bars before they were old enough is the President's right-hand man.

Schiller, media shy, declined to be interviewed for this piece.

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'Non-political'

"He was the most non-political guy," said Rich Siegel, an author who went to high school with Schiller. "This is the last thing I could have thought (for him). I don't think he gave a flying you-know-what about politics."

Schiller spent the first 18 years of his life in New York's Hudson Valley, attending New Paltz High School and graduating in 1977.

Friends described Schiller as a charismatic and determined guy who had endless friends but limited academic ability. When asked whether he ever thought Schiller would end up working at the White House, John Ford, his high school football coach, laughed and gave a blunt answer: "No."

"Who would have thought?" Ford said. "I just didn't think he would reach that lofty of a position. But you never underestimate a kid. Kids change after they get out of high school."

Schiller, sculpted and more than 6 feet tall at age 18, was an accomplished high school athlete, Ford said. He played defensive end in football and power forward in basketball, showing promise in both.

Siegel, who played basketball with Schiller in high school, said the high schooler's real talent was his unflinching courage to "mix it up" on the court, a tendency that extended into life off the hardwood.

"I spent a lot of time at bars with him," Siegel said. "If he thought something was wrong, he was ready to get his fists in there. ... There was never a fight he strayed away from."

Schiller's willingness to "throw his body around," Siegel added, was not because he craved conflict, but rather because Schiller felt protective over those close to him.

"I was a small little kid," Siegel said with a laugh. "He always protected me. He wasn't looking for trouble, but he was the kind of guy who would embrace it when it happened."

Growing up quickly

Siegel, Ford and others described Schiller as some who grew up fast in New Paltz, in large part, because his mother -- Loretta -- died of cancer in 1975. This forced Schiller, who was the middle child of five, to grow up quickly and take on responsibility to help his father. His father later died in 2007

"He had to grow up really, really fast" and lived in "a little bit of chaos," Siegel said.

Friends weren't surprised, then, when the standout athlete decided to join the Navy out of high school.

Based on his service record, obtained from the Navy, Schiller had an unremarkable four-year service. He served primarily at the Little Creek base in Norfolk, Virginia, and spent time on the USS Plymouth Rock, a landing ship for amphibious vehicles.

Schiller left active duty in 1982 and spent two years in the reserve. Returning to New York, Schiller had a dilemma: The onetime "high school cut-up," as his former football coach described him, needed a career.

Schiller, after volunteering as a counselor through his church, got an interview at the New York State Division for Youth, where he worked as a counselor for eight years. At night, though, Schiller was a cop at the Plattekill Police Department -- his true love.

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NYPD

After eight years as a counselor, Schiller, now well into his 30s, took the test for the New York Police Department and enrolled in the police academy in 1992. After a brief stint as a transit officer, Schiller then moved to working as a patrol officer in northern Manhattan, where his career really took off. After two years as a patrolman at a time where northern Manhattan was the epicenter of the cocaine trade, Schiller decided to go undercover.

His career was short, by his own admission.

"What happened was, as you can imagine, the big white guy walks into the projects looking to buy a vile of crack or some weed and it was a tough sell at the time," Schiller told Siegel in an interview that the author published online during the presidential election.

Three months undercover -- after planning to spend two years on the beat -- Schiller moved back to his precinct and joined the Street Narcotics Enforcement Unit. The beat fit the former high school heavy.

"I was the rammer," Schiller told Siegel, describing his job as busting into drug houses up to three times a night. "To me, it was an exciting career. ... I couldn't get enough of it."

Schiller also spent time in the high-intensity drug-trafficking area, where he worked under then Lieutenant David E. Chong, now the public safety commissioner for the City of White Plains, New York.

Chong, who approved Schiller working with Trump initially, remembers the detective as a devoted, physical and loyal officer who, he said, always had his boss's back.

"I would have kept Keith with me forever if I could have," Chong said. "He always had my back. I was always very comfortable knowing he was around."

Chong said Schiller's strength and size was an obvious asset, but it was his loyalty that set him apart.

"I can see the qualities that somebody like Mr. Trump, or the President of the United States, would see in a man like that and keep him around so long," Chong said.

Schiller regularly handled wiretaps, search warrants and large scale seizes of drugs, the commissioner said, meaning he spent a few days a week presenting evidence at the Manhattan district attorney's office.

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Meeting Trump

It was there that he was connected to Trump.

Schiller, as he tells it, was at the district attorney's office in 1999 when he saw Marla Maples, Trump's second wife, who was in to meet with an assistant district attorney.

Schiller, as he told Siegel, was looking for side work to supplement his NYPD salary when he saw Maples' body guard and thought: "If he is a body guard, I sure as f*** am a body guard, right?"

"A light goes off: Body guard, I can do this," Schiller said. "You wouldn't have wanted to meet this guy in a dark alley. Especially back then."

Schiller asked the assistant district attorney to put in a good word with Trump. He did, and the Trump Organization brought him on for a one-month trial.

"If you work out well with Mr. Trump, you will stay, and if it doesn't work out, well, nothing personal," Schiller recalled. "And I am still here."

Schiller said the job was an "eye opener" for a guy who grew up in New Paltz. He would go with Trump to dinners, fashion shows and baseball games -- always restricting who got close to the boisterous businessman. Schiller moved up the ladder with Trump, from temporary employee to body guard to Trump's head of security in 2005.

The job has taken Schiller around the world and shaped him into the person he is today. He described his persona as "very calculated" during the interview with Siegel, in part because he knew his role was "not to be on camera."

As Trump entertained and then eventually launched a run for president, Schiller found himself on camera a great deal. And not always for positive reasons.

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Crowd control

When Jorge Ramos tried to ask Trump a series of questions at a news conference in 2015, Schiller was the muscle who physically escorted the journalist out the room. The video was everywhere -- as was Schiller.

Schiller's instincts to "mix it up" as his old friend said, were on full display in September of that year when protests descended on Trump Tower. Schiller emerged from the building and grabbed a sign that read: "Trump: Make America Racist Again" from demonstrator Efrain Galicia.

Galicia gave chase and tried to grab the sign back before Schiller turned on a dime and punched the man in the face. The body guard then returned to the tower -- calmly.

"This man thinks he can do whatever he wants in this country, and we're going to stop him," Galicia said in Spanish based on video that was also seen around the world.

Schiller has said he relies on his "gut" to determine who in a crowd is dangerous.

"We have a saying in my business there is always a bad guy in the crowd, you can never assume that everyone is totally safe," he said. "I can walk into a room and I can pretty much feel and I know who the guys that we need to be concerned about. You can feel it. You just know."

Photos: Donald Trump's rise President-elect Donald Trump has been in the spotlight for years. From developing real estate and producing and starring in TV shows, he became a celebrity long before winning the White House. Hide Caption 1 of 37 Photos: Donald Trump's rise Trump at age 4. He was born in 1946 to Fred and Mary Trump in New York City. His father was a real estate developer. Hide Caption 2 of 37 Photos: Donald Trump's rise Trump, left, in a family photo. He was the second-youngest of five children. Hide Caption 3 of 37 Photos: Donald Trump's rise Trump, center, stands at attention during his senior year at the New York Military Academy in 1964. Hide Caption 4 of 37 Photos: Donald Trump's rise Trump, center, wears a baseball uniform at the New York Military Academy in 1964. After he graduated from the boarding school, he went to college. He started at Fordham University before transferring and later graduating from the Wharton School, the University of Pennsylvania's business school. Hide Caption 5 of 37 Photos: Donald Trump's rise Trump stands with Alfred Eisenpreis, New York's economic development administrator, in 1976 while they look at a sketch of a new 1,400-room renovation project of the Commodore Hotel. After graduating college in 1968, Trump worked with his father on developments in Queens and Brooklyn before purchasing or building multiple properties in New York and Atlantic City, New Jersey. Those properties included Trump Tower in New York and Trump Plaza and multiple casinos in Atlantic City. Hide Caption 6 of 37 Photos: Donald Trump's rise Trump attends an event to mark the start of construction of the New York Convention Center in 1979. Hide Caption 7 of 37 Photos: Donald Trump's rise Trump wears a hard hat at the Trump Tower construction site in New York in 1980. Hide Caption 8 of 37 Photos: Donald Trump's rise Trump was married to Ivana Zelnicek Trump from 1977 to 1990, when they divorced. They had three children together: Donald Jr., Ivanka and Eric. Hide Caption 9 of 37 Photos: Donald Trump's rise The Trump family, circa 1986. Hide Caption 10 of 37 Photos: Donald Trump's rise Trump uses his personal helicopter to get around New York in 1987. Hide Caption 11 of 37 Photos: Donald Trump's rise Trump stands in the atrium of the Trump Tower. Hide Caption 12 of 37 Photos: Donald Trump's rise Trump attends the opening of his new Atlantic City casino, the Taj Mahal, in 1989. Hide Caption 13 of 37 Photos: Donald Trump's rise Trump signs his second book, "Trump: Surviving at the Top," in 1990. Trump has published at least 16 other books, including "The Art of the Deal" and "The America We Deserve." Hide Caption 14 of 37 Photos: Donald Trump's rise Trump and singer Michael Jackson pose for a photo before traveling to visit Ryan White, a young child with AIDS, in 1990. Hide Caption 15 of 37 Photos: Donald Trump's rise Trump dips his second wife, Marla Maples, after the couple married in a private ceremony in New York in December 1993. The couple divorced in 1999 and had one daughter together, Tiffany. Hide Caption 16 of 37 Photos: Donald Trump's rise Trump putts a golf ball in his New York office in 1998. Hide Caption 17 of 37 Photos: Donald Trump's rise An advertisement for the television show "The Apprentice" hangs at Trump Tower in 2004. The show launched in January of that year. In January 2008, the show returned as "Celebrity Apprentice." Hide Caption 18 of 37 Photos: Donald Trump's rise A 12-inch talking Trump doll is on display at a toy store in New York in September 2004. Hide Caption 19 of 37 Photos: Donald Trump's rise Trump attends a news conference in 2005 that announced the establishment of Trump University. From 2005 until it closed in 2010, Trump University had about 10,000 people sign up for a program that promised success in real estate. Three separate lawsuits -- two class-action suits filed in California and one filed by New York's attorney general -- argued that the program was mired in fraud and deception. Trump's camp rejected the suits' claims as "baseless." And Trump has charged that the New York case against him is politically motivated. Hide Caption 20 of 37 Photos: Donald Trump's rise Trump attends the U.S. Open tennis tournament with his third wife, Melania Knauss-Trump, and their son, Barron, in 2006. Trump and Knauss married in 2005. Hide Caption 21 of 37 Photos: Donald Trump's rise Trump wrestles with "Stone Cold" Steve Austin at WrestleMania in 2007. Trump has close ties with the WWE and its CEO, Vince McMahon. Hide Caption 22 of 37 Photos: Donald Trump's rise For "The Apprentice," Trump was honored with a star on the Hollywood Walk of Fame in January 2007. Hide Caption 23 of 37 Photos: Donald Trump's rise Trump appears on the set of "The Celebrity Apprentice" with two of his children -- Donald Jr. and Ivanka -- in 2009. Hide Caption 24 of 37 Photos: Donald Trump's rise Trump poses with Miss Universe contestants in 2011. Trump had been executive producer of the Miss Universe, Miss USA and Miss Teen USA pageants since 1996. Hide Caption 25 of 37 Photos: Donald Trump's rise In 2012, Trump announces his endorsement of Republican presidential candidate Mitt Romney. Hide Caption 26 of 37 Photos: Donald Trump's rise Trump speaks in Sarasota, Florida, after accepting the Statesman of the Year Award at the Sarasota GOP dinner in August 2012. It was shortly before the Republican National Convention in nearby Tampa. Hide Caption 27 of 37 Photos: Donald Trump's rise Trump appears on stage with singer Nick Jonas and television personality Giuliana Rancic during the 2013 Miss USA pageant. Hide Caption 28 of 37 Photos: Donald Trump's rise In June 2015, during a speech from Trump Tower, Trump announced that he was running for President. He said he would give up "The Apprentice" to run. Hide Caption 29 of 37 Photos: Donald Trump's rise Trump -- flanked by U.S. Sens. Marco Rubio, left, and Ted Cruz -- speaks during a CNN debate in Miami on March 10. Trump dominated the GOP primaries and emerged as the presumptive nominee in May. Hide Caption 30 of 37 Photos: Donald Trump's rise The Trump family poses for a photo in New York in April. Hide Caption 31 of 37 Photos: Donald Trump's rise Trump speaks during a campaign event in Evansville, Indiana, on April 28. After Trump won the Indiana primary, his last two competitors dropped out of the GOP race. Hide Caption 32 of 37 Photos: Donald Trump's rise Trump delivers a speech at the Republican National Convention in July, accepting the party's nomination for President. "I have had a truly great life in business," he said. "But now, my sole and exclusive mission is to go to work for our country -- to go to work for you. It's time to deliver a victory for the American people." Hide Caption 33 of 37 Photos: Donald Trump's rise Trump faces Democratic nominee Hillary Clinton in the first presidential debate, which took place in Hempstead, New York, in September. Hide Caption 34 of 37 Photos: Donald Trump's rise Trump apologizes in a video, posted to his Twitter account in October, for vulgar and sexually aggressive remarks he made a decade ago regarding women. "I said it, I was wrong and I apologize," Trump said, referring to lewd comments he made during a previously unaired taping of "Access Hollywood." Multiple Republican leaders rescinded their endorsements of Trump after the footage was released. Hide Caption 35 of 37 Photos: Donald Trump's rise Trump walks on stage with his family after he was declared the election winner on November 9. "Ours was not a campaign, but rather, an incredible and great movement," he told his supporters in New York. Hide Caption 36 of 37 Photos: Donald Trump's rise Trump is joined by his family as he is sworn in as President on January 20. Hide Caption 37 of 37

New role

As Trump's campaign caught fire, Schiller's role in protecting the presidential candidate diminished almost entirely when the Secret Service began protecting Trump. Instead of protecting his boss day-to-day as he had done for years, Schiller now acted as a liaison between the Secret Service and the Trump campaign.

There were points of friction, former campaign aides tell CNN, especially initially when Schiller's old role was diminished. But those same aides said the former body guard grew into his more management role.

"It really has been a great experience working with them," Schiller told Siegel about the Secret Service.

Over time, Schiller and Trump have grown a personal relationship, White House and campaign advisers said. While they wouldn't call them best friends, many described Schiller as the man who can anticipate Trump's desires -- no small task -- and react.

Hope Hicks, Trump's White House director of strategic communications and former campaign spokeswoman, lauded Schiller for his commitment to Trump through thick and thin.

"Keith is a valuable member of the team," said Hicks, who has known Schiller three years. "He is a trusted aide who has been fiercely loyal to the President for many years. We are lucky to have him with us at the White House."

Former Trump campaign manager Corey Lewandowski said he would regularly turn to Schiller when he needed to understand a quirk or eccentricity about Trump.

"Any time I wanted to understand something, I would ask Keith," Lewandowski said. "I valued him for all the roles he played."

The Trump-Schiller relationship, Lewandowski said, was even stronger.

"That is a person who has, for a very long period of time, demonstrated his loyalty to Mr. Trump," he said. "I think if you have spent 18 years with person, working side by side with them, you develop a relationship and a friendship that both agree is very important."

There was, though, an arc to Trump's relationship with Schiller. Former Trump employees, who didn't want to talk about Schiller on the record, said -- at first -- he was "just the security guy" who was somewhat unremarkable to Trump.

But as time went on, the trust grew into not only a key position in Trump's latest venture -- the White House -- but into a friendship.

"He was always the man in charge of Donald Trump's security, but during the years of service, he also became a confidant, and it is almost like neither realized it," said a former Trump Organization employee. "What they have left is a really strong personal bond."