Police are searching a Colorado landfill for the remains of a woman whose fiance is charged with her murder, the AP reports. Authorities said their search for evidence or the remains of Kelsey Berreth that began on Tuesday could take weeks. The site is about 90 miles south of Denver. Berreth, the 29-year-old mother of a daughter with the suspected killer, was last seen near her home near Colorado Springs on Nov. 22. Patrick Frazee has been charged with the flight instructor's murder. He has not entered a plea to the allegations. Investigators testified during a Feb. 19 court hearing that Frazee's girlfriend told police he used a baseball bat to fatally beat Berreth, then burned her body and planned to dump the remains in a landfill or river. (More on the case here.)