In the Florida courtroom, the first-degree murder defendant is dwarfed by the cops who surround him. In the interrogation room, he can barely sit still or stay awake.

This defendant is 12 years old and, if convicted, could spend the rest of his life in prison.

His name is Cristian Fernandez, and he is the youngest person to be charged with murder as an adult in Jacksonville's history.

“Yes, I have compassion for Cristian Fernandez, but it's not my job to forgive,” State Attorney Angela Corey said. “It's my job to follow the law."

Police say the crime was premeditated, that Fernandez intentionally killed his 2-year-old brother, David, by violently shoving him into a bookshelf twice, causing a skull fracture and massive internal bleeding. 

The medical examiner ruled David’s death a homicide, caused by blunt-force trauma. Their mother, Biannela Susana, was not home at the time of the incident. Police say as David lay on his bed unconscious, his older brother called their mother, who then came home.

What happened next is very much at issue.

Susana, 25, is charged with aggravated manslaughter of a child and felony child abuse. She remains in jail on a $1 million bond and, if convicted, faces up to 30 years in prison.

Police say they have a confession from Cristian, but the case still has sparked international outrage. More than 170,000 people have signed an online petition urging the prosecutor to treat the 12-year-old as a juvenile, not as an adult. The prosecutor disagrees and says she is following Florida law.

The Sunshine State sends more juveniles into the adult prison population than any other state. In 2009, according to the Bureau of Justice Statistics, 393 Florida juveniles entered adult prison. Florida was followed by Connecticut with 332 such cases, North Carolina with 215, New York with 190, Arizona with 157 and Texas with 156.

“He’s just a kid,” said Alicia Torres, whose son was a classmate of Cristian's. She signed the petition, too. "He's got a baby face. ... He doesn't know -- he doesn't know what's going on."

Complicating the Fernandez case is the role of Susana. Police say during the several-hour window between when she came home and drove David to the hospital, her laptop shows that she searched “when some (sic) gets knocked out” at 10:54 a.m. “When your unconscious for hours” at 2:15 p.m. At 2:38 p.m., “concussions on children.” 

Then there were online searches for a Wachovia Bank account. At 2:39 p.m., the search was for “mayoclinic.com.” After that, according to the police report, someone downloaded music, searched popular screen savers, went to YouTube and then finally “St. Luke’s Hospital, Jacksonville, Florida” at 3:07 p.m.

A doctor at St. Luke’s told a police officer that had the toddler been treated sooner, he may have survived.

Cristian Fernandez’s public defenders argue all of the blame belongs with the mother, and Fernandez does not deserve to be prosecuted in the adult system.

"I think many would argue that she's the most culpable when it comes to the death of this child," Matt Shirk said.

In light of a plea deal that may spare this 140-pound murder defendant from the adult system, Fernandez will next be in court Oct. 31. His trial date has not yet been set.

The mother is scheduled to stand trial starting Feb. 27.

Phil Keating joined Fox News Channel (FNC) in March 2004 and currently serves as FNC's Miami-based correspondent.