Lisa Monahan, News 9

EDMOND, Oklahoma -- A mother calls on police to give some answers in the death of her child. The Medical Examiner ruled the death of nine-month-old Jake Hedger as a homicide.

The autopsy report shows Jake died from blunt force trauma to the head. The report does not specify what time the injury occurred, so it is unclear if the injury happened in the care of the babysitter or the parents.

Leah Hedger, Jake's mom, believes the police have made little progress in the case because no arrests have been made in the last seven months.

"What we have had to do is investigate this ourselves because we want to know what happened," Hedger said.

Edmond Police say they are investigating but the parents are not cooperating. A spokesperson for police told News 9 the parents refused a polygraph and some interviews.

An attorney for the parents provided a document that shows the parents did pass a polygraph test in April, just one month after Jake died. The Edmond Police say the Hedgers have not submitted to a test at the police department,

"Polygraphs are not admissible in court but the Hedgers submitted to one anyway for that reason alone police should not need a second polygraph," the parents' attorney Kevin Butler said.

Hedger feels like the allegations made by police are not only false but have also made the grieving process more difficult,

"I'm ready for it to evolve in to something more cause Jake needs that and I need that and his dad needs that," Hedger said.

Edmond police did not say if the babysitter in the case has agreed to interviews or a polygraph test. The babysitter's lawyer says he believes the injury occurred 48 hours before Jake's death but the autopsy does not state a specific time.