The second pair of hands were his, he used the split screen and editing, there are loads of tutorials about cloning/split screen on Youtube. LM was a member of the group against cruelty to animals, he knew they scrutinised these abuse videos right down to the background noise/sounds (Russian TV programme and the Little Drummer Boy record played by serial killers Brady & Hindley while torturing a little girl), the doorknob, vacuum cleaner, bedspread, the poster, the puppy and python etc.
He played the Hansel & Gretel game of leaving breadcrumbs, he sends them on a wild goose chase, what country is he in? he's in the Ukraine, no, Russia..... and wait, there's another pair of hands, must be another person in the room? He enjoyed the chase and misleading his followers, he loved the movie, Catch Me if You Can.
He was obsessed with Basic Instinct in which Michael Douglas starred, and there's a character called Manny in it. LM visited a lawyer who he imagined resembled Douglas and there began his story. My first thought when Manny was mentioned was Casey Anthony and Zanny, the non-existent nanny, not knowing of the Manny in Basic Instinct, but there is something uncanny about these liars and fantasists, the story begins well before their crime and arrest.
Imo, LM and his mother share some of these delusions and she fostered them since his childhood, blurring fantasy and reality. She never imagined he'd kill kittens and a human being, but she was up for the rest, LM becoming a model, a celebrity, rich and famous by whatever means, prostitution or w/e.
There's CCTV of LM's apartment block and where the bins are kept, 'Manny should' have been sighted but of course, he wasn't, because he doesn't exist.