The proper transliteration of Russian names into English has been debated as long as Russian literature has been translated into English. While there may not be a "correct" way to transliterate, SEEJ has a few guidelines for how transliterated names appear in the journal.
The common spellings of specific authors are allowed (i.e., transliteration is not necessary). For example:
Leo Tolstoy (Lev Tolstoy is also acceptable)
The names of fictional characters must be transliterated according to the Library of Congress transliteration table. Please see the section on transliteration for additional tables for other languages.
However, when quoting from a book passage, do not alter the original text. If the translation you are quoting uses Dmitry, that is how the name must appear inside the quotation. But when referring to the character in your own words, you must conform to the Library of Congress transliteration.