Chad Isaak a Washburn, N.D., chiropractor, is charged with four felony counts of murder. 7:16 pm, May 5, 2021 × Robert Quinn (right), the now-former defense attorney of Chad Isaak, 47, of Hazen, N.D., withdrew himself from the case Thursday, April 29, after he determined there was a conflict of interest between him and his client. WDAY file photo MANDAN, N.D. — A chiropractor accused of killing four people at a Mandan business over two years ago is at risk of losing his current defense team and said he is considering representing himself in court. Bismarck attorney Robert Quick said Wednesday, May 5, in Morton County District Court he has no choice but to file a motion to withdraw as counsel for Chad Trolon Isaak, 46, after his client filed a complaint against him.