JACKSONVILLE, Fla. — A decade before he was charged with murder, a 2-year-old Cristian Fernandez was found naked and dirty, wandering a South Florida street. The grandmother taking care of him had holed up with cocaine in a messy motel room, while his 14-year-old mother was nowhere to be found.

His life had been punctuated with violence since he was conceived, an act that resulted in a sexual assault conviction against his father. Fernandez’ life got worse from there: He was sexually assaulted by a cousin and beaten by his stepfather, who committed suicide before police investigating the beating arrived.

The boy learned to squelch his feelings, once telling a counselor: “You got to suck up feelings and get over it.”

Now 13, Fernandez is accused of two heinous crimes himself: first-degree murder in the 2011 beating death of his 2-year-old half-brother and the sexual abuse of his 5-year-old half-brother. He’s been charged as an adult and is the youngest inmate awaiting trial in Duval County.

If convicted of either crime, Fernandez could face a life sentence — a possibility that has stirred strong emotions among those for and against such strict punishment. The case is one of the most complex and difficult in Florida’s courts, and it could change how first-degree murder charges involving juvenile defendants are handled statewide.

Underscoring the unusual nature of the case, Fernandez’ defense attorneys said they aren’t sure how to proceed since the U.S. Supreme Court threw out mandatory life in prison without parole for juvenile offenders in June.