Iowa judge delays sentencing for Cristhian Bahena Rivera, convicted of Mollie Tibbetts' 2018 murder William Morris, Des Moines Register 'She had room in her heart for everyone': Mollie Tibbetts' loved ones keep her memory alive Replay Video UP NEXT DES MOINES, Iowa — The judge overseeing the case of Cristhian Bahena Rivera, convicted in May of murdering University of Iowa student Mollie Tibbetts, has delayed his sentencing after defense lawyers filed new motions claiming the state withheld relevant information about the case. On Tuesday, his attorneys filed another motion alleging that prosecutors had failed to disclose another investigation in the summer of 2018, when Tibbetts disappeared, into a man living less than 30 miles from Tibbetts' hometown of Brooklyn who was allegedly operating a sex-trafficking ring. Defense attorneys also wrote that at least 10 children have gone missing in and around Poweshiek County in recent years.