TULSA, Okla. (AP) — A trial date has been set for one of two brothers charged in the stabbing deaths of five family members in their northeast Oklahoma home.

An April 16, 2018, trial date for 18-year-old Michael Bever on five first-degree murder charges was set Monday in Tulsa County District Court.

Police say Bever and his brother, 20-year-old Robert Bever, fatally stabbed their parents, their 12- and 7-year-old brothers and their 5-year-old sister in 2015 in their home in the Tulsa suburb of Broken Arrow as part of a plot to begin mass killings across nationwide.

A 13-year-old sister survived the attack and a 2-year-old sister was unharmed.

Michael Bever has pleaded not guilty while Robert Bever pleaded guilty to the charges last year and was sentenced to life in prison without parole.