MARTINEZ — The 20-year-old son of a slain El Cerrito couple is fighting to speak against imposing the death penalty on the uncle who killed his parents, testing for the first time a state law that gave crime victims a greater voice in legal proceedings.

Eric Rogers is scheduled to testify for the prosecution next week during the penalty phase of the murder trial of Edward Wycoff, a 40-year-old Sacramento County truck driver convicted Monday of two counts of first-degree murder for killing his sister and brother-in-law, Paul and Julie Rogers, on Jan. 31, 2006.

While legal precedent limits Eric Rogers to testifying only to the impact the murders have had on his life, Rogers said he wants to tell jurors that he doesn't want Wycoff executed. His parents were strongly opposed to the death penalty, as is he, he said.

"I think revenge would bring me closer to the status of my uncle and further from the status of my parents," Eric Rogers told the Times. "To be vengeful in their name would be disrespectful."

Rogers hired Berkeley attorney Ted Cassman to argue that he has a right to voice his opposition to capital punishment under Marsy's Law, also known as Proposition 9 or the Victim's Rights and Protection Act of 2008, which voters approved last November. Marsy's Law gives victims the right to be heard at any legal proceeding.

Beyond Rogers' belief that the death penalty is wrong, such a sentence would cause Rogers more pain by subjecting him to 10 to 20 years of appeals on Wycoff's behalf, Cassman said.

Wycoff prosecutor, Mark Peterson, argues that case law states that jurors need to decide whether a defendant deserves death, not how a death sentence would impact others. Wycoff, acting as his own attorney, argued that the Rogers couple deserved to be killed because they treated him badly. He told the court that he's not taking a position on his nephew's challenge because Cassman never returned his phone calls and is, therefore, a "dirt bag."

"I would be all for it. I want to be in the law book, I'd be famous," Wycoff said. "I'm a vindictive man. I return evil for evil."

Judge John Kennedy said he will be rule on the issue Monday. The Northern California chapter of the American Civil Liberties Union and the California Crime Victims for Alternatives to Death Penalty will be monitoring the outcome.

"To our knowledge this is the first time this issue has ever been raised in court in California," said Natasha Minsker, death penalty policy director for the ACLU. "This case shows that prosecutors are making decisions that do not necessarily reflect the interests of the families of victims."