People v. Jiminez
In People v. Jiminez, 187 Colo. 97, 528 P.2d 913 (1974), the supreme court held that, if a defendant knows of grounds for disqualification prior to trial but makes no objection or request for disqualification, he or she may not assert that ground as a basis for reversal.
The rationale for the decision was:
A defendant will not be permitted, as a matter of trial strategy, to conceal error during trial . . . and upon an adverse result assert as grounds for reversal the error he should have revealed to the court. (187 Colo. at 102, 528 P.2d at 916.)