TALLAHASSEE, Fla.

An appeals court on Friday ordered a third trial for two Florida A&M fraternity brothers accused of beating another student so hard that he had to have surgery on his buttocks.

The First District Court of Appeal ruled Friday that the trial judge made an error during jury instructions in the December convictions of Michael Morton and Jason Harris under a felony hazing law.

Morton and Harris were sentenced to two years in prison after a jury found they caused serious injury to Marcus Jones by striking him on the buttocks with canes during a hazing ritual. Jones also suffered a broken ear drum which later healed.

It was the second trial in the case, which was the first under a law passed in 2005. A jury deadlocked during the first trial.

The appeals court found fault with Circuit Judge Kathleen Dekker telling jurors that they had to decide whether Jones' injuries were serious or slight, without giving them an option of finding his injuries to be moderate.

``If the jury believed the defense experts, jurors could have concluded that Jones' injuries were worse than slight, but less than serious, and could have acquitted had the trial court not given such a limiting instruction requiring them to choose between 'slight' and 'serious,''' the judges wrote in their opinion.

Assistant State Attorney Frank Allman said he will prepare for a third trial and called the decision disappointing.

``The instruction that was given was fine. It was clear, it told the jury what they needed to know, it was an accurate statement of the law,'' Allman said.

A lawyer representing Jones in a pending civil suit said the facts have not changed in the case.

``With the proper definition, the jury will find the injuries were there to back up the charges,'' said Roosevelt Randolph.

A lawyer for Harris didn't immediately return calls for comment. No one could immediately be reached at the office of Morton's lawyer.