Prosecutors say they spoke with Jake and Romy Reiner, Nick's siblings.
Karmelo Anthony, now 19, was convicted of murder and sentenced to 35 years in prison after a jury rejected his claims of self-defense during a confrontation with Austin Metcalf in the stadium bleachers last year.
Nick Reiner is accused of fatally stabbing his parents at the family's home.
Luigi Mangione's state trial is just weeks away, set to begin on Sept. 8.
Judge Gregory Carro adjourned the conference after about 20 minutes without publicly providing more details about the process for selecting jurors.
A federal appeals court has issued a ruling blocking the construction of President Donald Trump's $400 million White House ballroom, concluding that congressional approval is needed for the project.