NPR's Wendy Kaufman reports from Laramie, Wyoming, where Aaron McKinney is on trial in the death of gay college student Matthew Shepard. The coroner testified today in graphic detail about the damage done to Shepard's head by at least 20 blows from a blunt instrument. Shepard was left comatose, tied to a fence. He died in a hospital six days later. One of his attackers pled guilty and is serving a life prison term. If McKinney is convicted, he could get the death penalty. McKinney's defense is that Shepard made a sexual advance to him, which triggered thoughts of sexual abuse McKinney had suffered as a child, and McKinney beat him in a fit of rage.