The appeals court disagreed, writing that "Utah courts have previously approved of experts relying on their training and knowledge to provide opinions that do not amount to medical certainty."
Kayson Bradley Merrill died in 2006 while in bed between his father, Trevor Collet Merrill, and his mother, Echo J. Nielsen, both now 28. The baby was put to sleep on his back, but found dead on his stomach. At 3½ months, he was too young to roll over on his own, evidence that "supports a reasonable inference that Merrill actually caused the infant to stop breathing by co-sleeping," according to Friday's opinion.
The parents were said to be heavy sleepers, and a pediatrician warned them against co-sleeping a day before the child's death.
They also had infant daughter who died 3 years prior while sleeping with her parents, though her death by positional asphyxia was listed as accidental.
The appeals court decided evidence of the first death could also be admitted at trial, over the objections of defense attorneys who argued it wasn't relevant and would prejudice the jury. The judges ruled it could show Nielsen knew the risks of sleeping with her baby.
An attorney for Nielsen declined to comment and Merrill's attorney did not return a phone call seeking comment.
Nielsen and Merill have both pleaded not guilty. Nielsen has a status conference set for Jan. 31.