Sure. Thanks for the question.
There is some scholarly literature on the Magnitsky Act in the U.S. I'm happy to send it on to the clerk of the committee, if that's helpful. There is one particularly accessible article written about this from the U.S.
I think it's safe to say that the U.S. Magnitsky Act was absolutely successful in getting Russia's attention and telling Russia that the United States was displeased. To the previous speaker who spoke about the different reasons that you implement sanctions, from a signalling perspective the signal was, I think, loud and clear. It appears that some assets may actually have been frozen and seized, but I think you would need to seek advice from the Americans about exactly what kind of financial assets they got out of it.
Beyond that, however, since Russia posthumously tried Mr. Magnitsky and then found him guilty of tax evasion, I don't think the act was at all successful at holding those responsible to account for Mr. Magnitsky's death.
Russia also retaliated with a series of measures against the United States, including banning American citizens from adopting Russian orphans. They also developed their own list of Americans who would be subject to Russian sanctions for what Russia said were human rights violations, including U.S. Army officials who ran Guantanamo Bay.
I think that overall Magnitsky had a signalling effect and was effective in that way, but I don't think that it deterred Russia and I don't think it punished those responsible for Mr. Magnitsky's death.