Casey Anthony Walks Free Next Week -- But Why?

Casey Anthony will get out of jail next week, despite being sentenced Thursday by Judge Belvin Perry to four years in prison for lying to police.

Because of credit for time served and good behavior while in jail prior to and during her trial for the murder of her daughter, in which she was found not guilty, Anthony will only have to remain in jail for one week.

Then, she will be a free woman.

Judge Perry and attorneys figured out the credit Anthony was due for her time served and good behavior while awaiting trial for the murder charge.

Casey Anthony has been in jail since October 2008. She was acquitted on the murder charge in the death of her toddler daughter Caylee on Tuesday. She was also charged with first-degree murder, aggravated child abuse and aggravated manslaughter charges and she was acquitted of those charges as well.