HOUSTON -- A father who said his 2-year-old son died from a fall in their northeast Harris County apartment was charged with his death, KPRC Local 2 reported Wednesday.

Harris County sheriff's deputies said Darius Smith called for help when his son, Zion, collapsed on the floor of their apartment in the 500 block of Normandy Street on Oct. 27.

Homicide investigators questioned Smith and determined that the evidence did not fit his story.

"All indications are that it's shaken baby syndrome. The child suffered severe brain damage and severe retinal hemorrhaging," said Sgt. Eric Clegg with the Harris County Sheriff's Office." We did investigate it at that time. It's been an ongoing investigation. We've just recently received the final reports from the medical examiner's office."

An autopsy revealed that Zion died from severe brain trauma.

Zion's mother was at work and not at home at the time.

Smith was charged with capital murder on Tuesday. He was booked into the Harris County Jail without bond.

Smith said nothing as he was led out of the Harris County Sheriff's Office in handcuffs Wednesday.

Investigators said Smith's other son, Marco, died when he was 5 months old and in Smith's care. Detectives said no criminal charges were filed in that case. Officials do not know if that investigation will be opened again.