Sergey Aleynikov's court saga

Crime and Punishment: Sergey Aleynikov's court saga

• June 2009: Aleynikov quits Goldman Sachs after being hired by Teza Technologies. Prosecutors alleged he stole Goldman's computer code on his last day at work.
• July 2009: Aleynikov is arrested after returning to Newark Liberty International Airport. Teza suspended Aleynikov after his arrest and eventually terminated him.
• February 2010: He is indicted and pleads not guilty to charges that he stole Goldman's computer codes.
• December 2010: Aleynikov is convicted by a jury and later sentenced to eight years in federal prison.
• February 2012: An appeals court overturns his conviction and Aleynikov is freed from prison in Fort Dix, N.J.
• August 2012: Aleynikov is arrested in New Jersey and later charged with a nearly identical crime by the Manhattan district attorney.

Source: WSJ research

Sergey Aleynikov and his lawyer, Kevin Marino, leaving court in Manhattan in August 2012

Mr. Aleynikov's troubles began in 2009, when after working for two years as a computer programmer at the New York investment bank, he accepted a $1 million-a year job programming computers to execute superfast trades for a Chicago start-up.

His world came crashing down on a July day at Newark Liberty International Airport in New Jersey when he was arrested and charged with illegally downloading 32 megabytes of computer code from Goldman's computers and sending it to a computer server in Germany. Federal prosecutors alleged that he downloaded the code to help him build a similar high-speed trading platform at Teza Technologies LLC, a start-up founded by Mikhail "Misha" Malyshev, a former executive at hedge-fund Citadel LLC.

Teza suspended Mr. Aleynikov after he was arrested and eventually terminated him.

He was convicted in December 2010. After a year in prison, an appeals court overturned his conviction, saying that taking the code may have violated his obligations to the company but wasn't a crime under the laws for which he was convicted.

It is rare, but not unprecedented, for prosecutors to charge a defendant who already has been convicted and served prison time, or a federal appeals court has overturned the conviction. The law permits it, though. A legal precedent known as "Dual Sovereignty" allows state and federal entities to prosecute what are essentially the same crimes. New York state also has built-in exceptions that allow prosecutors to charge people with the same crime, even if a case has already been adjudicated in federal court.