The resentencing hearing of Menendez brothers can move forward despite opposition from the district attorney, a Los Angeles court has ruled.
The brothers' attorneys are attempting to have them resentenced to a lesser term, which could potentially make them eligible for freedom.
Erik and Lyle were convicted of killing their parents in their Beverly Hills mansion in 1989, a notorious case that still divides Americans. They are currently serving life in prison without the possibility of parole in California.
Friday's ruling means a pair of high-profile hearings next week to decide whether the convicted killers will be resentenced, will continue.
Los Angeles District Attorney Nathan Hochman has voiced fierce opposition to resentencing the pair, after his predecessor put the process in motion just before the November election.
The brothers' effort is based on a California law that allows certain inmates who were aged under 26 at the time of their crimes to seek resentencing and potential parole eligibility - recognising that brain development continues into a person's mid-20s.
If the brothers are resentenced to 50 years to life as they have requested, it would make them immediately eligible for parole.
Lyle and Erik Menendez appeared for hearing remotely via a video stream from a San Diego prison. Both were dressed in blue prison jumpsuits and appeared nervous at times - looking down, rocking in chairs and taking deep breaths - as prosecutors recounted graphic details of the killings.
