JEFFERSON CITY, MO. (AP) -- The state Supreme Court has struck down a Missouri law that allowed prior child sex offenses to be used against defendants facing similar new charges.

The Supreme Court says evidence of prior criminal acts should never be used in court to try to prove a defendant's propensity to commit a crime. To do so, the court says, violates a constitutional protection that is vital to the integrity of the justice system.

Tuesday's unanimous decision comes in a Livingston County case of a man convicted of first-degree child molestation.

Attorneys for Donald Ellison had objected when the trial judge allowed prosecutors to admit evidence of his prior conviction.

The Supreme Court overturned Ellison's conviction and ordered a new trial.

(Copyright ©2007 by The Associated Press. All Rights Reserved.)