How do you tell a prospective landlord that you are interested in their apartment, but not wire them money?

I am an American student and I will be moving to Paris in a month. I am in a frantic apartment search, and am using websites such as Craigslist.org. Many of the replies I have been receiving tell me about the peoples’ apartments, and have pictures, etc. Most of them want me to wire them a security deposit in order to reserve the apartment, which I can understand because how do they know I am serious about their apartment? Well I don’t want to wire anybody money until I view the apartment personally and sign a lease, just trying to protect myself from a scam. But my dilemma is I cannot travel to Paris between now and when I need to be there for school. How can I show the apartment owner that I am TRULY interested without getting caught up in a scam where they run off with a security deposit?