Elementary- Sherlock Holmes and Watson

Lately I have started to watch the show Elementary on CBS.  It is a new twist on the Sherlock Holmes stories with a hip Sherlock Holmes kind of like a Robert Downey Jr. type with a few tattoos and trendy clothes.  He has a thing for the ladies and in the latest episode Lucy Lu who plays Watson who is his companion.

In this Episode Leviathon is about a safe that is impregnable.  Sherlock gets a visit from a gentleman at his home who wants his help to figure out how 4 criminals were able to break into this safe in the past.  The criminals were caught  and all were put in prison but wouldn't talk.  Recently another Leviathon safe was broken into so the owner of the company believes that there must be a 5th accomplice who worked with this master heist team.

Sherlock starts to look through the crime scene for clues.  He finds out that there is only one way to get into the safe and that is though a randomly assigned number generated and sent to the key fob of the owner.  The Owner was out of the country at the time so there is no explainable way that they could have gotten through the safe.

Sherlock sits in front of the safe for hours.  Watson (Lucy Lu) shows up and he bounces some ideas off her, it is 2 am and she needs to visit her brother tomorrow but she doesn't want to stay all night but has a loyalty to him so she stays.
He destroys the digital screen of the safe with an ax, I guess out of frustration.
Sherlock gives the people Lucy Lu's phone number and she asked why he gave them her number because they are wondering who took an ax to the safe.  He says"I didn't want them to contact me". He tells her if they call, it was a necessary part of the process.

He contacts the remaining 3 criminals for a visit so he can gather information but they have refused to talk to anyone.  One of the four have died so there are only 3 left.
Sherlock gets a visit with one of the lock pickers in Sing Sing and Sherlock and Watson visit him.  Sherlock persuades him to answer how they got in.  All he has for them is an Alias name

They follow the lead and visit the house of the possible suspect. When they get there Sherlock finds a original van Gogh hidden behind a fake painting as the suspects son comes in.  He informs Sherlock that his father is innocent and there is no way he could have done any crime because he had a stroke 2 years ago and can not speak and is just immobile.
Sherlock stated that they have been put on a snipe hunt.
They continue following up on leads and the mystery continues.  Every lead they follow is leading them to a dead end.  What will be the piece for Sherlock to solve this puzzle? Watch the full episode here on CBS.