A teenage mother has been charged with murdering her toddler son last month in Kearns.

Adrianna Lucero, 17, called paramedics Aug. 24 and said her son had gone into cardiac arrest and stopped breathing while she went to get him JELL-O at their home near 5500 West and 5100 South, police said.

Alejandro Gabriel Lucero, 2, was flown to Primary Children's Medical Center where he died.

In charges filed Thursday in 3rd District Court, investigators said Adrianna Lucero was responsible for the severe spinal injury that killed her son — an injury likely caused by a "severe, bending force" that "would have taken some time to inflict."

Lucero told police she was watching a movie with Alejandro, her boyfriend and their 5-month-old son when Alejandro's eyes rolled back and he fell to the ground unconscious, according to court documents.

The woman said her son was a healthy child, but that she had taken him to the hospital a week earlier because he had stopped walking for a time. In charges filed Thursday, the state medical examiner said the boy appeared to have been abused before. Alejandro had rib fractures that were healing and an old back injury that could have been caused by the same method of abuse that killed him, according to the charges.

Lucero has been charged with murder, a first-degree felony, and two counts of child abuse, a second-degree felony. If convicted, she could face life in prison.

Lucero's boyfriend, Sergio Martinez-Gonzales, 26, has been charged with second-degree felony obstruction of justice. The man told investigators that he had left the room and when he returned, Alejandro was shaking and white, according to the charges. He said he did not see or hear anything.

The medical examiner said Alejandro's injuries would have taken some time to inflict, "during which (the boy) would have been screaming the entire time."

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