JACKSONVILLE, Fla. -

The death of 5-month-old Marvin Mobley -- found unresponsive at an apartment complex in June -- has been ruled a murder

Jacksonville Sheriff's Office detectives were called to the Southside Apartments in the 2300 block of Westmont Street. The boy was taken to Baptist Medical Center, where he died.

Homicide detectives at the time said there was no obvious trauma to the baby and the boy had possibly suffocated while in bed with his mother.  Police did not say what caused them to determine that the child was killed or if they are close to charge anyone with murder.