Clarification: There's no formal definition of the "butt drag," but coaches say it involves grabbing the butt cheek of a rival. Coaches vary on how often anal penetration occurs, but they say that it should never be intentional. The move does not involve skin-on-skin contact; the wrestler practicing the move is pushing his fingers against his opponent's uniform.

Correction: Preston Hill has not been expelled. He has been suspended pending an expulsion hearing.

In a crowded gym during practice in front of parents and coaches, the Buchanan High School wrestler tackled a teammate and executed a move his coaches taught him.

He inserted his fingers between the boy's buttocks.

It's called the "butt drag," in which a wrestler grabs a rival's butt cheek and puts fingers in the anus to get leverage. The move is widely used at matches around the country and has been around for decades.

But now it is at the center of an uproar after Buchanan High wrestler Preston Hill was expelled and charged with a sex crime for using it on a teammate.

"It just doesn't make sense," said Preston's father, Darren Hill. "His coaches taught him the move when he was in middle school. All the wrestlers use it and my son did it in front of his coaches at a school-sponsored event."

Clovis police, however, say 17-year-old Preston went too far. A police report says that at a July 15 practice, he molested a Buchanan freshman teammate by inserting his fingers deep into the boy's anus, causing him pain.

The boy's father, Ross Rice, said Preston is a bully who targeted his 14-year-old son because he stood up to Preston in an earlier encounter. Now, Preston's friends are teasing the boy at school, Rice said. The Bee is not naming Rice's son because of the allegation that he is the victim of a sex crime.

"Preston took it beyond a simple wrestling move," Rice said. "He crossed the line."

The Fresno County District Attorney's Office has charged Preston with sexual battery. His trial begins Thursday in Fresno County Superior Court.

The case has some scratching their heads.

Former Fresno State coach Dennis DeLiddo said the butt drag is a common move used by wrestlers all the time. "I've never heard this move used as being ugly or dirty," he said.

On Friday, DeLiddo was at a wrestling tournament in Las Vegas. During a telephone interview, he said, "a coach just yelled out butt drag" to encourage one of his wrestlers to use it.

District Attorney Elizabeth Egan declined to comment. But Michael Idiart, a former assistant Fresno County district attorney, said he would not have filed criminal charges because wrestlers know that once they get on the mat, they are consenting to pain -- and sometimes embarrassment.

"If this is a legitimate and recognized wrestling move, the DA has no case," he said.

But if bullying had occurred, Idiart said, school officials should address it in a reasonable fashion: "Kids do stupid things. They shouldn't have their lives ruined."

Clovis Unified School District officials said they couldn't comment because of laws that protect minors.

Not the first case

The butt drag has been in the news before.

In 2007, a 17-year-old South Dakota high school wrestling champ was charged with rape and attempted rape after six wrestlers testified that he penetrated or tried to penetrate their anuses.

A lawyer for Jerome Hunt said he was employing a legitimate wrestling move called the butt drag, which is also known as "checking the oil."

Hunt's lawyer described those acts as horseplay, but the judge characterized the teen as a bully. The boys testified that it usually happened before practice, while wrestlers goofed around until coaches arrived.