Casterline's attorney asked for the delay, which was granted by the judge last week. Casterline faces a first-degree murder charge for the Oct. 4 stabbing of 68-year-old Virginia Barone.
Casterline's mother, 41-year-old Shelley Casterline also was charged in the murder. She pleaded guilty to a reduced second-degree murder charge in March. She is scheduled to be sentenced on June 10.
Investigators have said Shelley Casterline acknowledged she'd killed Barone after the older woman made comments that enraged her. Barone was the mother of Shelley Casterline's live-in boyfriend. She was found partially covered by boards in her Guide Rock home on Oct. 5 with more than 20 stab wounds.
Andrew Casterline's trial, which was originally scheduled to begin on May 27, will now start Sept. 8.