There is a wide spread rental scam where people rent out properties that they don't own or even sometimes don't exist. Some of the tip offs are that they are out of town and can't show the property, they want payment by untraceable means such as Western Union or Moneygram, etc. You can check property records online to verify who actually owns the property. Also, if they ask for money and then tell you they are going to mail you the keys, run away.