MANDAN, N.D. (AP) — A sentencing date has been scheduled for the man convicted of killing four people at property management business in Mandan in 2019. Chad Isaak is scheduled in court Dec. 28 where he faces the possibility of life in prison on each of his four murder convictions. A Morton County jury in August found Chad Isaak guilty in the deaths of RJR Maintenance and Management co-owner Robert Fakler, and employees Adam Fuehrer, Bill Cobb, and his wife, Lois Cobb. The four were shot and stabbed April 1, 2019, in the RJR building in Mandan. Isaak lived at a Washburn property managed by RJR, but a definitive motive for the slayings was never established.