A Peoria man pleaded guilty Monday just before his trial was to begin to sexually assaulting a woman more than a decade ago. Clarence L. Triplett, 34, pleaded guilty to aggravated criminal sexual assault in connection with the October 2002 incident involving a 17-year-old woman. The plea will send him to prison for at least 16 years and possibly up to 55 years when he is sentenced later this year.