A state medical examiner has ruled the death of Sequatchie, Tenn., 3-month-old Colin Eugene Russell a homicide.

"The injuries seen in this case involving multiple areas of the body in varying stages of healing are consistent with repeated, nonaccidental trauma and a diagnosis of battered child syndrome," the autopsy report filed May 2 by associate state medical examiner Bridget Eutenier states. "In my opinion ... the cause of death in this case is blunt force injuries of the head and neck. The manner of death is homicide."

Now prosecutors are studying how to proceed.

The investigation began June 17, 2012, after relatives made an emergency call when Colin stopped breathing.

The child was taken to Grandview Medical Center in Jasper, then transferred to Vanderbilt Medical Center in Nashville. Officials said early on that medical staff described the infant's injuries as "major trauma" to his brain. The family discontinued life support on June 23, 2012.

Authorities say Colin's father, Chris Russell, is a "person of interest" in the case.

Marion County Sheriff's Office Detective Beth Raulston said Thursday that investigators just got the final autopsy report and the next step is to review it with the 12th Judicial District Attorney's office.

Raulston predicted that evidence would be presented to the Marion County grand jury but said that decision lies with the district attorney's office.

The 12-page autopsy report notes contusions on the child's head, injuries that included blood clotting in several areas of his brain and "extensive" hemorrhaging in the optic nerves of both eyes.

The report also notes Colin had at least 15 fractures of his ribs and a fractured right clavicle, along with a ligament injury on his spine that appeared to have been healing.

In a case summary, the report also notes remarks made by the parents to medical officials during the child's treatment.

The baby's mother, Leah Collins, told medical officials the infant was diagnosed with an ear infection about a week before his initial hospitalization and was on antibiotics when he was taken to the hospital, the report states.

"His mother also reported that she had fallen onto the bed and landed on him a few weeks prior," the report states. "His father reported ... he had struck the infant's head against the steering wheel of the car a few weeks prior but no bruising or swelling or changes in behavior was noted after that incident."

Contact staff writer Ben Benton at bbenton@times or 423-757-6569.