Sheriff Randall Edwards says 25-year-old Joshua Steven Durcho was moved into isolation "for his own safety." He is allowed visits only from his court-appointed attorney, Matthew Haire.
Edwards says Haire has visited Durcho at least once.
Durcho is being held without bail on five counts of first degree murder in the January 12 deaths of Summer Rust, her son and her three daughters at their El Reno apartment. His preliminary hearing is scheduled for February 25.
A judge has entered a not guilty plea on Durcho's behalf.
A funeral is planned Wednesday for Rust and her children.