I hope that the arrest does lead to a charge, it would at least mean that her family would know who was behind taking this young woman's life and see justice served.
I cannot begin to imagine what these poor people are going through, what they must be feeling and thinking - it must be agony.
I too thought the landlord looked a little "odd" and seemed very "upbeat" - you would imagine most people so close to Joanna would be shocked/concerned/frightened/sad but that's not basis enough to point the finger at him as everyone deals with grief differently. I would think the police have enough evidence, more then we're aware of, to arrest him at this stage.
Whatever the outcome from this arrest I hope that Joanna's family and boyfriend are getting lots of support. I hope that this doesn't drag on too long for them and that they can lay their daughter to rest and start to process everything that has happened to them. They're in my prayers.