A DNA analyst testified Friday that blood discovered in the trunk of Cristhian Bahena Rivera’s car matched that of Mollie Tibbetts, a University of Iowa student who was abducted and killed in 2018.
Bahena Rivera, 26, is on trial for first-degree murder in the death of Tibbetts, 20, who went missing while running in Brooklyn, Iowa, in July 2018.
A month later, her body was discovered, and the cause of death was ruled to be “homicide resulting from multiple sharp force injuries.”
Tara Scott, a criminalist in the DNA section of Iowa’s crime lab, told jurors Friday she analyzed a swab taken from a blood stain found in Bahena Rivera’s Chevy Malibu and it matched the profile of Tibbetts’ blood.
She also said many of the stains found in the trunk of the suspect’s car contained DNA from multiple people, were too weak and contaminated to conclusively include or exclude anyone as a match — and that DNA evidence can be degraded by a number of factors, which could have affected Tibbetts’ body.
Bahena Rivera told police to approach Tibbetts when she was running in 2018, but he doesn’t recall what happened after that, and he pleaded not guilty after being convicted.
Defense attorneys argued in court on Friday that his partial confession was fabricated and forced as a result of sleep deprivation and aggressive interviewing tactics, and they showed recordings of Bahena Rivera sleeping after the 11-hour investigation.