At last finally i saw the latest episode
Bob is not RJ he is a friend to him ...
i think that bob doesn't want to know who is RJ he wants to know where is RJ
as if he wants to know Rj identity he simply ask lennon about his name!!
Bob wants something from RJ may be ( money -  Revenge  - ...etc ) so
he killed Lennon as he afraid that if Lennon talk about Rj Identity , RJ may be caught or killed >> BOB wants RJ alive !!
bob searched jane room as he may take some thing lead to RJ
Jane and Bob wants the same thing to find RJ but Bob has an advantage as he is already Knows who is Red John
thanks