Entertainment Tonight special correspondent Marcia Clark exclusively tells ET her candid thoughts on O.J. Simpson's recent guilty verdict, saying justice has finally been served.

"I was surprised by the verdict," Marcia admits. "[Simpson] has been getting away with it, so to speak, for a long time."

Marcia was the face of the prosecution in the Simpson murder trial and authored a book about the case titled Without a Doubt. She calls the day Simpson was acquitted for murder a "miserable day."

In this recent case, Marcia is confident Simpson will serve time, saying, "I think it's fair to say that he'll do at least seven to eight years in state prison."

Simpson was recently found guilty of armed robbery, kidnapping and 10 other counts in Las Vegas last Friday -- a development that could land him in jail for the rest of his life.

Nevada prosecutors said the disgraced football star rounded up five men last year -- two of them packing guns -- and robbed two sports-collectible dealers in Las Vegas.