In September a jury found Jorge Banda guilty of shooting and killing Tulare County Sheriff's Detective Kent Haws.
Wednesday the public defender asked a judge for a new trial based on certain questions and behavior in court between the prosecutor and judge that they felt was inappropriate.
The judge denied the request.
Banda killed Haws in December 2007 during a traffic stop while the detective was on his way home from work.
Banda is set to be sentenced in December and faces life in prison.