Texas prosecutors say they will not charge Alan and Laura Shatto whose adopted Russian son’s death was ruled an accident.
Max Shatto, adopted from a Russian orphanage, died in January age three, soon after Russia banned US adoptions.
A grand jury had found insufficient evidence to charge Alan and Laura Shatto, a prosecutor said.
The case sparked outrage in Russia, where authorities have launched their own investigation and demanded the Shattos face charges.
Texas doctors who examined the boy ruled his death had been an accident and that bruises on his body were self-inflicted.
According to preliminary results of a post-mortem examination released this month, Max Shatto died accidentally from a torn artery in his abdomen and had bruises consistent with injuring himself.
No drugs or medicines had been found in his body and the coroner said he had had a mental disorder that caused him to hurt himself.
Max Shatto, adopted from a Russian orphanage, died in January age three, soon after Russia banned US adoptions
Earlier this month, more than 10,000 people marched in Moscow to demand a halt to all foreign adoptions of Russian children.Max Shatto, born Maksim Kuzmin, and his younger brother Kristopher were adopted from an orphanage in north-west Russia last year by the Shattos, who live in Gardendale, Texas.
Laura Shatto said she had found him unconscious outside the family’s home and he died later in hospital.
When Max Shatto died, Russia’s children’s commissioner Pavel Astakhov alleged he had been murdered by his adoptive mother.
But the Shattos’ lawyer said the toddler had suffered from behavioral issues and occasionally butted his head on objects or other people.
Kristopher still lives with the Shattos.
In December, the Russian government banned adoptions of Russian orphans by Americans. Correspondents say Russia did so in retaliation for the US passing a law allowing Russian officials suspected of human rights abuses to be banned from the US.
US ambassador to Russia Michael McFaul has warned against “the sensational exploitations of human tragedy” after Russian officials accused an American woman of murdering her adopted Russian son, Max Shatto.
Michael McFaul said the US had been working behind the scenes with Russian diplomats after Max Shatto’s death.
Three-year-old Max Shatto died in January. He was adopted from a Russian orphanage.
Officials and parliamentarians have regularly used the death to justify a recent ban on adoptions to America.
In a blog post on Friday, Michael McFaul said that he was “distressed about a number of issues surrounding the tragic death”, including the way that the US and its diplomats were being portrayed by some Russian commentators.
The ambassador said that “a thorough investigation to discover exactly what happened to Max was still under way” and that investigators are abiding by an important principle in American society: “the idea that one is innocent until proven guilty”.
Michael McFaul added that while he was “saddened and appalled” that 20 children adopted from Russia to the US over the last two decades had died, he was proud that more than 60,000 others “have had the opportunity to enjoy loving parents, new families, and countless opportunities in America”.
“It is time for sensational exploitations of human tragedy to end and for professional work between our two countries to grow, on this issue and many others,” Michael McFaul said.
Russian officials and parliamentarians have regularly used Max Shatto’s death to justify a recent ban on adoptions to America
News of Max Shatto’s death led to an angry reaction in Russia, where he was known as Maxim Kuzmin.
Outraged officials said that he may have been badly beaten and abused.
Russia’s top investigative body on Wednesday opened a murder inquiry into the case.
Earlier in the week, the Russian children’s commissioner went on Twitter to say that Max Shatto had been murdered by his adoptive mother Laura Shatto.
Russia banned adoptions to the US from the beginning of January in retaliation for an American law know as the Magnitsky Act – which blacklists Russian officials accused of rights abuses.
The US act was named after anti-corruption lawyer Sergei Magnitsky, whose death in Russian custody became a symbol of the fight against corruption in Russia and soured relations between the two countries.
Some 3,400 Russian children were adopted by foreign families in 2011, with almost a third of the children going to American homes.
In the past two decades, Americans have adopted more than 60,000 Russian children.