Jurors were shown gruesome crime-scene photos Tuesday at the trial of an Arizona man charged with killing his brother in a drug dispute and fatally shooting his 6-year-old nephew who had witnessed his father's death.

A prosecutor making closing arguments in the case against Christopher Rey Licon showed an image of young Xavier Jaquez's body in the Phoenix alley where he was killed in December 2010 and later found by sanitation workers. He was seen lying on his back, surrounded with a pool of blood.

The jury also saw photos of the boy's father, Angel Jaquez, as he lay dead on a sofa in the Phoenix townhome he shared with Licon, his half-brother.

Authorities are seeking the death penalty against Licon, who has mounted an insanity defense. His lawyers say Licon had a psychotic episode around the time of the killings.

Prosecutor Laura Reckart told jurors that Licon "has never been crazy or nuts."

Investigators believe Jaquez was shot in the back of the head as he watched TV and that the child was in the home when the killing happened. They say the boy either saw the crime or heard his father get killed.

Police say Xavier kicked and screamed as his uncle pulled him away, forced him into a car and drove to the alley 20 miles away.

Licon, then a construction management student at Arizona State University, told investigators that he was studying at a library in the Phoenix suburb of Tempe when his half-brother was killed. But Licon's alibi collapsed quickly after police interviewed neighbors and gathered other evidence, authorities say.

Prosecutors say Licon was in an illegal drug business with Jaquez and had acknowledged selling drugs in the months preceding both deaths.

After Reckart finishes her closing arguments, defense attorneys are scheduled to speak to the jury.