Italy's highest criminal court ruled that Amanda Knox, acquitted of murder in Italy, will have to be tried again.
The decision sets up years of legal wrangling for Knox. The next trial will be in Florence, but more appeals are possible
Americans see it as double jeopardy to be re-tried after being acquitted but University of Washington Law Professor Mary Fan says many countries allow it.
"It's not unusual in other systems in the world for the prosecution to appeal an acquittal and even succeed as they have here," she said.
Fan says Italy could have legal grounds to extradite if Knox were ultimately convicted. But the decision would be up to U.S. courts and the State Department.
Sen. Patty Murray is cautious about what lies ahead.
"Obviously, it's a huge impact on her and her family and I'm sure it's a very tough day for them. We'll have to see what the process is moving forward,” she said.
Knox's attorney says the next trial won't be until the end of this year, possibly even 2014, and the legal wrangling could go on for years.