That witness, a pediatric neurologist from Baltimore, says he believes the four-month-old died from complications caused by a blood clot in his brain.
Benefield's charged with injury to a child causing death in the February 2012 death of Lucas Benefield.
He's also on trial for the alleged continuous violence against his wife.
The doctor testified that in looking at the victim's records, he believes a blood clot occurred in the vein of the child's brain which then caused a seizure and then caused the child to stop breathing.
In his opinion, he says the infant died of lack of oxygen to the brain.
The doctor says CT scans and MRI's support his findings because there is no impact injury seen on those scans.
He testified if the infant had been shaken, his brain scans would show trauma to the brain.
During testimony for the prosecution, medical experts said they found multiple bleeds in the infant's brain, multiple fractures that were in the process of healing, and hemorrhages in both eyes.
Prosecutors claim Benefield, the victim's primary caregiver, caused those injuries by shaking him.
Defense testimony continues tomorrow morning.
Copyright 2017 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.