CINCINNATI -- It's been almost a year since the death of 15-month-old Elijah Obrecht Jr. was ruled a homicide, and no one has been charged. Investigators believe the infant's mother and her boyfriend could know more than they're telling.

Faith Phifer, brought her son's unresponsive body to Christ Hospital, where he was pronounced dead. She said she and Elijah spent the previous night at the Walnut Hills home of her boyfriend, Keith Tabron. She claimed she put Elijah to bed safely that night, but his face was blue and his breathing had stopped by the time she woke up.

Phifer insisted during a sit-down interview with Ashley Zilka that she was innocent of any wrongdoing in the boy's death.

"He was my world," she said. "It wasn't a lie. It wasn't a coverup. It wasn't anything. At the end of the day, that was my baby."

Cincinnati Police Detective Eric Karaguleff said that the cause of the boy's death was head trauma.

"This isn't something that you are going to roll over on your pillow the wrong way and cause an injury of this nature," he said. "This isn't from a fall or anything. The coroner's office and I have discussed what might cause these injuries, and the feeling is, the injuries we are seeing would be inflicted by somebody."

Tabron was arraigned Thursday for possessing illegal firearms at the time of Elijah's death; Karaguleff was watching.

"Our feelings, based on everything we know about that investigation at this point, is that Faith and/or Keith would have the answers to the question we are looking for," he said.

Phifer's attorney says she has spoken to investigators three separate times without counsel and denies any wrongdoing or involvement in her son's death.

Anyone with information about this homicide should call Crime Stoppers at 513-352-3040.