HOUSTON — A Texas appeals court has ruled that a man convicted of murder after jurors rejected his "stand your ground" self-defense claim didn't get a fair trial and deserves a new one.

Raul Rodriguez, 49, has been serving a 40-year prison term for the May 2010 slaying of a 36-year-old man during an argument over loud music in a rural Harris County neighborhood northeast of Houston.

The 1st Texas Court of Appeals ruled Thursday that the instructions given to the jury in Rodriguez's 2012 trial, before deliberations, were too confusing.

The function of the jury charge "is not merely to avoid misleading but to lead and prevent confusion," a three-judge panel of the court said in a 39-page ruling. It said the jury charge was far from the way instructions should be: clear, concise and to the point. It returned the case to the trial court for a new trial.

"At the heart of our criminal justice system is the right to a fair trial. Raul was denied this right due to incorrect jury instructions," defense attorney Neal Davis told the Houston Chronicle (http://bit.ly/1H1pRKv ). "Now Raul will have the chance to have a fair day in court."

Prosecutors said they were disappointed and likely would appeal the ruling.

"This was a hard-fought conviction that we had hoped would stand," said Clint Morgan, a Harris County assistant district attorney.

In a 22-minute video he recorded the night of the shooting, Rodriguez, a retired Houston firefighter, can be heard telling a police dispatcher he called that "my life is in danger now" and "these people are going to go try and kill me." He then said, "I'm standing my ground here," and shot Kelly Danaher.

Rodriguez's reference to standing his ground was similar to the claim made by George Zimmerman, a Florida neighborhood watch volunteer who cited that state's stand-your-ground law in his defense. He was acquitted of murder for the February 2012 fatal shooting of an unarmed teenager, Trayvon Martin.

Texas' version of the law is known as the Castle Doctrine and was revised in 2007 to expand the right to use deadly force by allowing people to defend themselves in their homes, workplaces or vehicles. It also says a person using force cannot provoke the attacker or be involved in criminal activity at the time.