SALT LAKE CITY -- The murder trial for a teenage mother accused in the death of her son has begun.
Defense attorneys say someone else murdered the 2-year-old, but prosecutors tell a different story, and as prosecutors made their opening statements to the jury, the suspect, Adrianna Lucero, began to cry.
Prosecutors say Lucero was overwhelmed caring for three young children. They say on Aug. 24 she took the 2-year-old victim to her then boyfriend's house, where the boy began to twitch and collapsed.
Prosecutors say ex-boyfriend Sergio Martinez-Gonzalez didn't see what happened to the child, but he will testify about what led up to events that day.
Defense attorneys say Martinez-Gonzales killed the toddler. He walked out of the courtroom as Lucero's attorney talked about abusive behavior against Lucero and the child.
During a preliminary hearing in December, Utah's chief medical examiner testified the boy's spine was severely bent until it broke. The medical examiner also found signs of past abuse on the boy including rib fractures and an old back injury.
Prosecutors charged Martinez-Gonzalez with obstruction of justice, but the charge has been dismissed. They have twin boys together who are currently in state custody.
When asked if he thought Lucero was a good mother, the ex-boyfriend said he couldn't answer that. He said it was a difficult case for him.
Prosecutors say the trial is expected to last for a few days and could go to the jury on Thursday.