Robert Durst's lawyer has moved for a mistrial.

Durst is on trial in California for the murder of his best friend Susan Berman. Durst's lawyer claims he “cannot physically ensure testifying.”

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A doctor says Durst's "death in the next six months would not be surprising.”

The Westchester DA said the new development "does not impact the work we are doing to conduct our investigation toward a possible grand jury presentation. "