"I no longer wish to parent this child," the note read, calling the boy a liability.
"This child is mentally unstable," Hansen wrote to the Russian Ministry of Education. "I was lied to and misled by the Russian Orphanage workers and director regarding his mental stability and other issues."
Adopted six months ago, the boy was traveling on an expired U.S. visa. He was taken to a hospital for a medical evaluation. Video footage showed Artyem looking bewildered as he is taken from the police station to the hospital by Russian social service workers.
"On every level, putting a little kid on a plane and shipping them somewhere is horrific behavior. If you have a problem, you deal with the problem," said Adam Pertman, executive of the Evan B. Donaldson Adoption Institute. "It is certainly the equivalent of abandoning your child."
While he understands the knee-jerk reaction in Russia to protect their children, Pertman said banning all adoptions isn't the way to go.
"There are lessons to be learned from this," he said. "Ensuring that all the other kids that need loving homes don't get them is not the way to solve the problem."
Bedford County Sheriff Randall Boyce told ABC News Friday that he had tried to visit Torry Hansen on Thursday and Friday, but was told by Hansen's lawyer "they said they will meet with us later, sometime next week."
Boyce said, "This is a touchy deal and I'm not sure if anything illegal has been done or not. Our plan is to have the adoption agency check with the people in Moscow or whatever part of Russia they're in and check with this child and see if they see signs of abuse."
Boyce said he intended to move slowly and carefully in his investigation.
"We're breaking new ground here," he said. "There may be no crime at all when you really get down to it. Maybe some bad judgment in the way she turned this child back."
The Tennessee Department of Child Services (DCS) also is looking into elements of the case.
"DCS looks into child abuse and neglect," said Rob Johnson, the department's director of communications. "By statute we look into cases alongside law enforcement. We look at it from a child welfare point of view.
"We have tried to visit the Hansen family," Johnson added. "We are working alongside law enforcement on trying to interview them."
Of particular interest to DCS would be the safety of any children that may be in the Hansen home, Johnson said.
"We do not track international adoptions," Johnson said. "They are private adoptions."
Artyem, who turns 8 next week, "was accompanied from his home in Tennessee to Washington by his American grandmother, who put him on a direct flight to Washington to Moscow," U.S. embassy officials told ABC News. Nancy Hansen put the child on the plane with the note from her daughter.
She told the AP that the child began hitting, kicking and spitting and making threats in January.
"He drew a picture of our house burning down and he'll tell anybody that he's going to burn our house down with us in it," Hansen said. "It got to be where you feared for your safety. It was terrible."
Nancy Hansen said she and her daughter, a single mother, went to Russia together to adopt the boy, and she believes information about his behavioral problems was withheld from her daughter.