A coroner's jury has ruled that a Cheyenne baby who died while in the care of his mother's boyfriend on June 30, 2015 died of undetermined causes.

The jury, which was comprised of three Laramie County residents, heard nearly six hours of testimony from 16 witnesses during an inquest conducted Tuesday by Laramie County Coroner Ron Sargent.

"The whole sole purpose of this is to determine the cause and manner of death, to give the family closure and to be able to fulfill the requirement to fill out the death certificate," said Sargent.

According to witness testimony, Tyler Child was watching the 6-month-old boy (C. L.) and his 3-year-old sister (A. L.) on the night of June 30, when he called 911 to report that the baby didn't appear to be breathing. An autopsy ruled the boy's cause of death as undetermined.

"People get a misconception that science has advanced to the point where there are no secrets," said Sargent. "There may be no physical evidence or any reason that a doctor, a forensic pathologist or a toxicologist can determine the cause and manner of a death, that's why we hold the inquest."

The coroner's jury deliberated for about an hour before reaching their verdict, which has no civil or criminal trial significance.

"They listened to all the testimony, they reflected on all the different elements of the chemical testing, the doctor's testimony, all the things that came into the case and ruled it as undetermined," said Sargent. "It's understandable that they were undecided, it's a very complex case."

Child has been charged with manslaughter in the case and could face up to 20 years if convicted. His trial is scheduled for March 1 in Laramie County District Court.