DENVER -- Opening statements got under way in the first-degree murder trial against Jon Phillips.

Phillips was the legal guardian of Chandler Grafner, 7, who died in May 2007 of a heart attack.

Prosecutors said Grafner's death was the result of Phillips locking the boy in a linen closet and depriving Grafner of food and water for weeks.

"(Phillips) denied him food, denied him water, and left him there to sleep in his urine, in his own feces," said prosecutor David Lamb.

Lamb said the boy was put in the confined space after reporting abuses at home to his teachers.

Lamb said Grafner came to school with a blackened ear and when asked how it happened the boy said, "Daddy clobbered me."

Phillips obtained custody of Grafner after his girlfriend, Christina Grafner, lost custody of the boy.

Grafner and Phillips had a child, Dominick Phillips, 5, who authorities did not want to see separated from his half brother.

The defense, however, argued Phillips is not to blame for Grafner's death.

David Jones, Phillips' attorney, said Grafner had diabetes. Jones said the disease ate away at Grafner's body and left it in its emaciated state and eventually killed him.

Prosecutors said the boy was 34 pounds at the time of his death and his body temperature was 84 degrees when he arrived at the hospital. They said he had been dead for hours and Phillips failed to call 911 for help. Instead, they said, he cleaned up evidence of the closet in an effort to hide Grafner's neglect.

Testimony in the case continues Wednesday.