Sergei Magnitsky was a lawyer who investigated the agencies of the Russian government that looted the British firm Hermitage Capital Management. On June 4, 2007, police from the Ministry of the Interior raided the offices, taking all the records and the corporate seal. They then turned over all the assets to various criminal gangs. Hermitage hired Sergei Magnitsky from the law firm of Firestone Duncan to investigate. Magnitsky was arrested and held in prison without charges until he died in 2009, after 359 days, one day short of the legal maximum that you can be held without being charged in Russia. Now, although dead, Magnitsky is being tried for embezzlement.
The Magnitsky Affair is why Russia canceled adoptions by Americans. The Magnitsky Affair is why Russia condemned large lots of US beef as “unfit for sale.” The Magnitsky Affair is the reason for the U.S. Senate bill called the “Sergei Magnitsky Rule of Law Bill” which was eventually made an amendment to H.R. 6156 normalizing trade with Russia, which President Obama signed into law on December 14, 2012.
Wikipedia biography of Sergei Magnitsky here.
The doctor who refused to treat him in prison was found not guilty of killing him. (The Independent UK here.)
Russia puts dead lawyer Sergei Magnitsky on trial. (Perth Now here.)
Wikipedia summary of the Magnitsky Bill as introduced in 2010.
The Government Printing Office PDF presentation of the law as signed by President Obama here.