Updated

An attorney for Daniel Marsh – the defendant convicted of brutally killing an elderly couple when he was 15 years old – argued in California's Third District Court of Appeals on Wednesday that Marsh should be released from prison next year under a state law that would make him eligible at age 25. 

That law is SB 1391, which took effect in 2019. It prohibits 14- and 15-year-olds from being tried as adults. Marsh was convicted in 2014 as an adult and sentenced to 52-years-to-life in prison. 

State deputy Attorney General Rachelle Newcomb argued that Marsh's judgment was finalized before SB 1391 took effect, so it can't be retroactively applied. 

"August 21, 2018, is when appellant’s judgment and prison sentence were final," Newcomb told the court. "Because that date was prior to the 2019 effective date of Senate Bill 1329, a law that is not applicable to defendants whose judgments are final, the appellant is not entitled to the benefits of that 2019 law."

DANIEL MARSH, CONVICTED OF MURDERING, MUTILATING ELDERLY CALIFORNIA COUPLE AS TEEN, SEEKS EARLY RELEASE

Mark Greenberg, Marsh's attorney, argued that a 2018 Yolo County Superior Court hearing on whether Marsh should have been tried as a juvenile amounted to a retrial. 

"The Attorney General claims that Mr. Marsh’s cert possibilities expired in August of 2018. That’s not true," Greenberg said. "Mr. Marsh, let’s assume that everything the court is intimating and the attorney general is saying about the finality of this judgment in October 2018, Mr. Marsh could have pursued a cert petition from that reinstatement of judgment."

Associate Justice Louis Mauro appeared to agree with the state that the judgment in the case was final. 

"You have a final judgment, don’t you? There’s nothing to appeal," Justice Mauro told Greenberg. "You’ve already had an appeal from that judgment."

SAN FRANCISCO DA FACES SECOND RECALL EFFORT AS RESIDENTS 'FED UP' WITH PROGRESSIVE 'ZERO CONSEQUENCE' POLICIES

Marsh was convicted in 2014 of murdering Oliver Northup, 87, and Claudia Maupin, 76. The victims – a husband and wife – were stabbed more than 60 times each. 

Marsh was 15 when, authorities say, he murdered and mutilated the elderly couple in Davis. Marsh had targeted their home after searching the area for open doors and windows to get to potential prey, according to FOX 40. He sliced a hole into a window screen at their home and looked on as his victims slept, the station has reported.

"This was not a crime of passion or juvenile impulse. It was a well-planned and executed random act of violence," Mary Northup, daughter of one of Marsh’s victims, said in 2018.

Investigators found no forensic evidence linking Marsh to the crime, but the teen confessed to authorities after another teen told police Marsh had been boasting about the slayings, the TV series "48 Hours" reported

Marsh allegedly told authorities he dreamed of being a serial killer and, according to FOX 40, told investigators he enjoyed the slayings. 

He pleaded not guilty, claiming insanity, and was tried as an adult in 2014, local reports state. 

CLICK HERE TO GET THE FOX NEWS APP

California's Third District Court of Appeals will meet in three months to give its decision on the case, the Fresno Bee reported

The Associated Press contributed to this report.