CBS Miami reports prosecutors believe that in March 2011, Fernandez acted with premeditation when he violently pushed his brother into a bookcase and beat him while his mother was out. The two-year-old victim died two days later from a fractured skull and bleeding in the brain.
Fernandez is the youngest person ever charged with first degree murder in Jacksonville.
Fox News reports a judge set February 27, 2012 as Fernandez's trial date, and it is unlikely the boy will be offered a second plea deal, meaning if he is convicted, he could face life in prison.
The prosecution offered a plea deal several weeks ago. Under that deal, Fernandez would have to admit to murder, and when he turns 21, he would be set free.
However, Fernandez's defense team deemed the deal unacceptable because their client would have to admit to murder, and might have to spend three years of that sentence in an adult prison. The defense is hoping the state's attorney will come back with a new plea deal, but that has not happened.
The boy's mother also faces a charge of aggravated manslaughter in her son's death. Biannela Susana, 25, first told police her son got injured in a fall, officers say. According to her arrest report, she put ice on the boy's head then looked up concussions on the internet, only calling for help hours later.
Both Cristian Fernandez and his mother remain held without bond.