A Manatee County mother accused of negligence in the death of her 4-year-old child was found guilty by a jury on Friday.

The verdict in the trial of Dianna Marr was announced shortly after 5 p.m. The jury deliberated for almost three hours prior to the reading of that verdict.

Marr had been charged with aggravated manslaughter of a child 18 years old or younger by culpable negligence.

Her son Alexander, 4, died from a brutal beating in 2015.

According to Marr's testimony, she put Alexander to bed at around 1:30 a.m. The next afternoon, Manatee County deputies were called after she and her live-in-boyfriend, Trevor Cardarelle, realized the boy was unresponsive.

According to the medical examiner, the child died after being beaten about the head and torso, leaving him with a fractured skull, brain trauma, and a lacerated liver.

Prosecutors said sleeping through that type of brutal attack was not possible, especially since it occurred in a bedroom next door to Marr's.

"The level of force, like a high-speed car crash, falling from a three-story window, that's the level of force used on that little boy within feet of his mother," said Deputy Assistant State Attorney Heather Doyle.

Throughout the week, Marr's defense pointed to Cardarelle as the accused killer. Cardarelle was also charged with aggravated manslaughter by culpable negligence, but a jury in October found him guilty of a lesser charge of culpable negligence.

Marr will remain in custody until her sentencing hearing on March 31. She could face up to 30 years in prison.

Bay News 9 reporter Lauren Verno is at the trial and will have more during this evening's newscasts.