A doctor from the state medical examiner's office testified Thursday that he believes 5-month-old Arthur Beason died last October as a result of a violent shaking.

Dr. Edward A. Leis, who performed the autopsy on the infant following his death Oct. 22, testified during the trial of Jose Parra, 23, who is charged with second-degree murder in the baby's death.Leis said he listed the cause of death as swelling of the brain and a lack of oxygen to the brain.

Dr. William M. Palmer, who has an office at Primary Children's Medical Center, where the baby was taken by helicopter, also testified that the baby's injuries were consistent with shaken-baby syndrome.

Defense attorney Milton Harmon asked Maria Beason, the baby's mother, on Wednesday about an automobile accident involving Parra, the baby and Beason's 2 1/2-year-old daughter, Sammi, a few weeks before the baby's death. Sammi had a cut lip, Parra had a lump on his head from hitting the windshield, but the baby, who was sitting on Parra's lap as Parra drove, appeared normal.

Leis said a broken clavicle, one of the infant's injuries, could have occurred in the accident, although it was unlikely, but the broken ribs could not.

Maria Beason testified that Parra, who lived with her, watched the children while she worked at Canyon Hills Care Center in Nephi. "He was good with the kids," she said.

"He tells me he loves the baby like it is his," she said.

On Oct. 16 the baby became ill, said Beason. He was taken to Dr. Nolan B. Money, Payson. Dr. Money testified he examined the infant and found he had infected ears and tonsils and prescribed an antibiotic. "I went over the baby head to toe," said Money. There were no external indications of abuse such as bruising, he said, and he found the baby irritable but alert.

On Oct. 17, said Beason, she stayed home and cared for the baby. On Oct. 18 she went to work at 2 p.m. At 5:30 p.m. Parra came running down the hallway at Canyon Hills calling her. She said she went to her car and found the baby pale. Nurses at the facility administered CPR.

Beason testified that Parra told her he had bounced the baby on his knee and the infant had accidentally fallen to the carpeted floor.

Palmer testified that would not not account for the injuries he saw. It would have taken aggressive, "totally inappropriate bouncing" to create such severe head trauma, he said.