Defense attorneys apparently have several issues with the judge, including remarks he has made about illegal immigration. Also, the judge's wife, Sandra Elliott, is a longtime assistant district attorney.
If Elliott again refuses to step down, defense attorneys can ask Oklahoma County's chief judge to remove him. The chief judge is a rotating position that will change several times before the end of the year.
If the chief judge refuses, defense attorneys then can ask the Oklahoma Court of Criminal Appeals.
Ersland was charged with first-degree murder after he shot a masked robber six times in May 2009 inside the Reliable Discount Pharmacy in south Oklahoma City. Killed was Antwun "Speedy" Parker, 16, of Oklahoma City.
Ersland has said he acted to defend himself and two female employees. Prosecutors say he went too far when he fired the last five shots, in effect executing an unconscious robber who was no longer a threat.
The judge was to have ruled Tuesday on a defense request to bar District Attorney David Prater from prosecuting the case. That hearing was postponed.