Mr. Santos, under scrutiny for lies about his background, is set to be sworn into Congress on Tuesday even as records, colleagues and friends divulge more about his past.In two years, George Santos went from being a little-known also-ran to a beacon of the Republican Party’s unexpected resurgence in a deep-blue state. But a swirling cloud of suspicion surrounds Mr. Santos, just as he is poised to take the floor of the House of Representatives on Tuesday, to swear to serve Constitution and country.Mr. Santos has admitted that he fabricated key parts of his educational and professional history, after a New York Times investigation uncovered discrepancies in his résumé and questions about his financial dealings. Federal and local prosecutors are investigating whether he committed crimes involving his finances or misleading statements. Now, new reporting shows that his falsehoods began years before he entered politics.Mr. Santos would join Congress facing significant pressure from lawmakers on both sides of the aisle.Mr. Santos has been hard to reach. He has not answered telephone calls, text messages or emails asking him to respond to The Times’s reporting. Earlier this week, Mr. Santos’s lawyer responded to an email asking about his campaign’s unusual spending, saying it was “ludicrous” to suggest the funds had been spent irresponsibly. Mr. Santos did not answer an email sent to him and his lawyer on Friday asking for comments about new reporting on the discrepancies in his past.Members of his own party have called for more detailed explanations of his behavior, and Nick LaLota, also a Republican representative-elect from Long Island, has called for a House ethics investigation.Representative James R. Comer of Kentucky, the incoming Republican chair of the House Oversight Committee, told Fox News on Thursday night that he was “pretty confident” that the House Ethics Committee would open an investigation into Mr. Santos. He added, “What Santos has done is a disgrace. He’s lied to the voters.”New York Democrats also made it clear they want to subject Mr. Santos to deeper scrutiny. Representative Hakeem Jeffries, the incoming Democratic leader, has said Mr. Santos is “unfit to serve.” Representative Ritchie Torres said he planned to introduce the Stop Another Non-Truthful Office Seeker Act — the SANTOS Act — that would require House candidates to provide details of their backgrounds under oath.The lawmaker who may have the most significant role in his future in the House, Kevin McCarthy, the House Republican leader, has been silent when asked about The Times’s reporting and Mr. Santos’s interviews supporting it.It remains unclear how the controversy might affect Mr. Santos’s debut in Congress, including his committee assignments. Mr. Santos told NY1 last month that he hoped to serve on the House Financial Services or Foreign Affairs committees, based on his “14-year background in capital markets” and a “multicultural background.” He has since admitted to misrepresenting his work in financial services, while aspects of his heritage have been called into question.New reporting by The Times brings a clearer picture of his earlier life into view, including information about the gaps in his personal history, along with discrepancies in how he described his mother’s life.Mr. Santos has said that he grew up in a basement apartment in Jackson Heights, Queens. Until Wednesday, Mr. Santos’s campaign biography said that his mother, Fatima Devolder, worked her way up to become “the first female executive at a major financial institution.” He has also said that she was in the South Tower of the World Trade Center during the Sept. 11, 2001, attacks and that she died “a few years later.”In fact, Ms. Devolder died in 2016, and a Brazilian community newspaper at the time described her as a cook. Mr. Santos’s friends and former roommates recalled her as a hardworking, friendly woman who spoke only Portuguese and made her living cleaning homes and selling food. None of those interviewed by The Times could recall any instance of her working in finance, and several chalked the story up to Mr. Santos’s tendency for mythmaking.His apparent fabrications about his own life begin with his claims about his high school. He said he attended Horace Mann School, a prestigious private institution in the Bronx, and said he dropped out in 2006 before graduating and earning an equivalency diploma. A spokesman for Horace Mann said that the school had no record of his attending at all.By 2008, court records show, Mr. Santos and his mother were living in Brazil, just outside Rio de Janeiro in the city of Niterói. Just a month before his 20th birthday, Mr. Santos entered a small clothing store and spent nearly $700 in 2008 dollars using a stolen checkbook and a false name, court records show.Mr. Santos has denied that he committed crimes in the United States or abroad. But the Brazilian record shows that he admitted the fraud to both the police and the shopkeeper.“I know I screwed up, but I want to pay,” he wrote in a message to the store’s owner on Orkut, a popular social media website in Brazil, in August 2009. “It was always my intention to pay, but I messed up.”In November 2010, Mr. Santos and his mother appeared before the police, where they both admitted that he was responsible. On Sept. 13, 2011, a Brazilian judge ordered Mr. Santos to respond to the case. Three months later, a court official tried to subpoena him, but he could not be found.By that time, he was back in New York, working at a Dish Network call center in College Point, Queens, company records show.Interviews with half a dozen former friends and colleagues, several of whom spoke on the condition that they not be identified to avoid being dragged into Mr. Santos’s controversies, suggest that he was reinventing himself when he moved back to New York, and that he would continue to do so in the years to come. They portray Mr. Santos as a striver, whose tendency toward embellishment and one-upsmanship left them with doubts about his many claimed accomplishments.He told some that he had been a journalist at a famous news organization in Brazil, but none could find his name on its website. He said that he was taking classes at Baruch College, but none of his friends remembered him studying. He bragged of Wall Street glory but often seemed to be short on cash, at times borrowing from friends whom he didn’t always repay. When he joined a travel technology company called MetGlobal, Mr. Santos portrayed himself as a man with family money. But two former co-workers said that the pay was modest and the work didn’t square with Mr. Santos’s depiction of himself as a financier passing time after bad bets left him on the outs on Wall Street.Not everything in Mr. Santos’s stated biography was a lie. A LinkBridge document supports his claim that he was a vice president. Several former colleagues confirmed he worked for MetGlobal, for a subsidiary called HotelsPro. And records examined by The Times appeared to corroborate his claim that he received his high school equivalency degree in New York in 2006.In 2016, Mr. Santos left for Florida, public records show, around the time that HotelsPro was opening an office in Orlando. Mr. Santos told Newsday in 2019 that he went there briefly for work. He received a Florida driver’s license and was registered to vote there in the 2016 election.Those who knew him recalled that Mr. Santos had long been a follower of Republican politics, and that he railed against Hillary Clinton and Bill de Blasio, who was then the mayor of New York.One who was close to Mr. Santos was Pedro Vilarva. Mr. Vilarva met Mr. Santos in 2014, when he was 18 and Mr. Santos was 26. Mr. Vilarva found him charming and sweet. They dated for a few months before Mr. Santos suggested they move in together. Mr. Vilarva said he felt on top of the world — even if he said he did find himself footing many of the bills.“He used to say he would get money from Citigroup, he was an investor,” Mr. Vilarva recalled. “One day it’s one thing, one day it’s another thing. He never ever actually went to work,” he said.Things began to unravel between the two men in early 2015, Mr. Vilarva said, after Mr. Santos surprised him with tickets to Hawaii that turned out not to exist. Around the same time, he said he discovered that his cellphone was missing, and believed Mr. Santos had pawned it.The betrayal prompted him to plug Mr. Santos’s name into a search engine, where he found that Mr. Santos was wanted by Brazilian police.“I woke up in the morning, and I packed my stuff all in trash bags, and I called my father and I left,” he said.Looking back, Mr. Vilarva said, he was young and gullible: He wanted to believe Mr. Santos’s many stories and believe in the life that they shared. Today he is worried about the impact Mr. Santos might have as an elected official.“I would be scared to have someone like that in charge — having so much power in his hands,” he said.André Spigariol More