Yes, Tatjana is Russian speaking and was residing in Brooklyn at the time of her disappearance.Just to confirm, Tatjana was a Russian speaker and lived in the Brooklyn/Brighton Beach area?
There was a con man and identity thief called Dmitriy Yakovlev who was involved in a few disappearances/deaths of Russian Speakers in this area. Irina Malezhik – The Charley Project
However, I think the Miami job may be key to working out what happened. It was a Japanese man who gave her the job?