The brothers shot Jose and Kitty Menendez in 1989, in what prosecutors in the ensuing trial said was a cynical attempt to get their hands on a large family fortune.
The Menendez brothers claim the killings were committed after years of abuse, including alleged sexual abuse by their father.
The new evidence included a letter allegedly written by Erik to his cousin detailing abuse, and allegations of abuse by Jose Menendez against another man.
Lyle, 57, and Erik, 54, can appeal Monday’s ruling.
Having had their original sentences of life without the possibility of parole reduced to 50-year terms in May, they will be eligible to apply for parole again in three years.
Their only other chance of sooner release is if California Governor Gavin Newsom grants them clemency.
-Agence France-Presse