Jockey Roman Chapa is facing a felony charge of unlawful influence on racing based largely on a photograph taken during a race earlier this month.

When Chapa won the Jan. 17 race riding Quiet Acceleration at the Sam Houston Race Park in Texas, a snapshot of the photo finish circulated. He reportedly asked that the image be taken down, raising suspicions.

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Prosecutors now allege that the photo showed Chapa, 43, holding a buzzer in his left hand. Buzzers are used to send an electrical shock to the horse.

Barry Abrams of ESPN's "In the Gate" said the alleged device was intended to startle the horse and make him run faster.

"It doesn't really hurt the horse," Abrams said. "It more gets his attention. … It's just meant to kind of startle him."

Investigators said the jockey told them that the picture was photoshopped by someone trying to frame him.

Abrams said incidents like this were not common.

"Just about all the tracks these days have stewards positioned all over the rack track - both with their own eyes and with cameras everywhere - so it's very difficult nowadays to execute such a thing effectively," he said.

AP

Chapa's track record is questionable. In 2007, he was suspended for using an electrical device on a horse. And in 1994, he was suspended for using a nail to make a horse run faster.

Chapa did not respond to requests for comment by ABC News.

Andrea Young, president of the Sam Houston Race Park, said in a statement that the park was "pleased" with how fast the investigation had moved.

"These sorts of actions have no place in horse racing, and are a disservice to the tens of thousands of people involved in our sport who play by the rules every day. We will continue to support this investigation in every way possible," Young said.

If he is convicted, Chapa faces up to 10 years in prison.

ABC News' Ryan Owens, Matt German and Shahriar Rahmanzadeh contributed to this story.