The woman never stated in the letter that he tried to kill her (she said he had severe psychopathic issues/behaviors), so I don’t know where you got your information.
I just read the article and didn’t find anything like that either.
Anna Orlova, a spokeswoman for Kremlin’s Children Rights Commissioner, told The Associated Press that she visited the boy and he told her that his mother was “bad,” “did not love him,” and used to pull his hair.