DENVER -- On Thursday, prosecutors in Denver began to seek justice for a 7-year-old boy who the coroner said was starved to death by the people who were supposed to care for him.

Chandler Grafner died in May weighing just 34 pounds.

Chandler's legal guardian, Jon Phillips, and his girlfriend, Sarah Berry, are charged with first-degree murder and child abuse resulting in death.

At a preliminary hearing in court on Thursday, the judge said he heard enough evidence to rule there was probable cause to try both Phillips and Berry for first-degree murder. The trial has been set for Sept. 24.

During the preliminary hearing, homicide Detective Larry Moore said Chandler "looked like a concentration camp prisoner. He was so thin, there was no body fat ... His eyes were sunken. His cheeks were sunken."

He told the court that the closet that the boy was locked in was covered in feces and smelled of urine.

Court documents obtained by 7NEWS in July included an interview with Chandler's younger brother. He said Phillips and Berry forced Chandler into a closet for days without food or water.

He also said they wouldn't let Chandler use the bathroom so he went in the closet, getting feces on himself and the walls and further angering his guardians.

When Chandler pleaded with his brother for food, the brother refused to get him any because he was afraid his parents would get mad at him.

The 5-year-old brother told detectives that Chandler was placed in the closet May 4 for taking food from the kitchen, and was left there until May 6 -- the day he died.

On May 6, Berry called 911 to report Chandler was not breathing. The Denver coroner ruled the boy died of starvation and dehydration. Prosecutors argue he died a slow, painful death, having been starved for at least a month.

Chandler was about 20 pounds underweight for the average 7-year-old boy. The coroner's report also states that Chandler had more than two dozen cuts, open sores and bruises on his body.

The defense is arguing that the boy had trouble gaining weight, even when he lived with other guardians. They say he had been abused before and had a history of "food issues," where he would hoard food and steal food and his guardians were only trying the best they could to deal with his issues.

Defense attorney Darren Cantor told 7NEWS that the case is not as clear cut as it might seem.

Neither Berry nor Phillips are biologically related to Chandler.

Chandler and his younger half- brother were removed from their mother's custody after she was deemed an "unfit mother" and was facing child abuse charges.

The boys were temporarily placed in their maternal grandmother's care. But at the beginning of the year, the Jefferson County Social Services then removed the boys from their grandmother's care and gave custody of both boys to Phillips, who is the younger brother's biological father.

The 5-year-old brother has been placed in foster care.