The logo of Swiss bank UBS is seen at an office building in Zurich. REUTERS

Tom Alexander William Hayes earned his nickname Rain Man, because, like the autistic character played by Dustin Hoffman in the 1998 film of the same name, the banker is known to be noticeably awkward and very good with numbers.

But the former star trader at UBS AG is better known as the face of the world's biggest banking scandal. Sure, other bankers are implicated in the scandal to manipulate the Libor, the world's benchmark lending rate. Two months ago, the U.S. Justice Department charged Hayes and fellow UBS trader Roger Darinwere of conspiracy, wire fraud and antitrust activity, alleging that individuals (plural) “known and unknown, did knowingly combine, conspire, confederate and agree to commit certain offenses against the United States.” And the U.S. Commodity Futures Trading Commission said in December that it recognizes others were involved.

But Hayes stands out, say financial regulators, who have called him the “connective tissue” that connects many players in the scandal, reports the Wall Street Journal.

The manipulation of the Libor might not raise any eyebrows in the general public, but minuscule movements of this key daily rate affects anyone who invests in securities or takes out loans. In other words, if it costs more to borrow because some suits -- known and unknown -- are playing games with the Libor, it’s a crime no different than pickpocketing borrowers and investors on a massive scale.

So what else do we know about Hayes, the fall guy du jour?

- He grew up in a London middle class family, studied computer programming and was sought after by a number of banks following his university graduation. His first job started in 2001 with Royal Bank of Scotland Group plc (NYSE:RBS) as a junior trader.

- He was known to dress more like a college student than a highly paid investment banker.

- He remains under investigation in London but was freed after a brief time in custody in December and has not been charged with a crime there. The U.S. wants him extradited.

- In 2006, he was hired by UBS AG (NYSE:UBS) to work at the Swiss bank’s Tokyo office. An acquaintance told the Journal that Hayes was unsettled at the rate-manipulation practices he witnessed there. However, it’s there that he allegedly began influencing the yen Libor rate while also investing in derivatives linked to the movement of the rate.

- He was hired by and then fired from Citigroup Inc. (NYSE:C) after Japanese regulators slapped the bank with a fine for trying to manipulate the Libor and Japanese rates. The bank is still facing investigations in Britain and the U.S. for these shenanigans.

- He doesn’t deny the allegations that between 2006 and 2009 amid the subprime mortgage debacle he was able to nudge the Libor up and down though his network of contacts with other banks and traders. What he says is that this manipulation was common practice done with the approval and encouragement of higher-ups. He is currently cooperating with Britain’s financial regulators to build a case against his superiors at RBS and other parties.