Updated December 16, 2025 at 1:04 PM EST
Many questions remain following the arrest of Nick Reiner. The 32-year-old is being held without bail on suspicion of murdering his parents, beloved Hollywood director Rob Reiner and his wife, Michele Singer Reiner.
Nick was arrested Sunday after Rob and Michele were found dead inside their Brentwood, Calif., home. The Los Angeles county district attorney's office is reviewing evidence in the killings.
Former Orange County homicide prosecutor Matt Murphy told Morning Edition the next step in the investigation is to determine whether Reiner, who is presumed innocent, has an "organic mental illness" or exhibited "bad behavior due to addiction." Reiner has spoken openly in recent years about substance abuse issues and recovery struggles.
"The difference is, fundamentally, from a prosecutorial standpoint, when you've got somebody who's born with or develops an organic mental illness, a lot of times their behavior isn't their fault, and it interweaves with a potential insanity defense," Murphy said.
In a conversation with NPR's A Martínez, Murphy explained why an insanity defense is "a much tougher bar to reach" for Reiner.
Listen to the full interview by clicking on the blue button above.
The radio version of this story was edited by Taylor Haney and produced by Nia Dumas. The web copy was written by Destinee Adams and edited by Obed Manuel.
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