Scapegoat

http://en.wikipedia.org/wiki/Scapegoat
The scapegoat was a goat that was driven off into the wilderness as part of the ceremonies of Yom Kippur, the Day of Atonement, in Judaism during the times of the Temple in Jerusalem. The rite is described in Leviticus 16.

Since this goat, carrying the sins of the people placed on it, is sent away to perish, the word "scapegoat" has come to mean a person, often innocent, who is blamed and punished for the sins, crimes, or sufferings of others, generally as a way of distracting attention from the real causes.