Legal experts around the nation anxiously are awaiting Silver's ruling. If she decides Comer's years of isolation at SMU II have rendered him incompetent, and appellate courts uphold her ruling, other death row inmates being held in super-max units are likely to be affected.
The judge is expected to rule in a few weeks.
Robert Comer historically has been a defense's attorney's nightmare -- uncommunicative, unsympathetic and guilty of the crimes with which he's been charged.
Records show Comer spent little time with his court-appointed attorney after his 1987 arrest for murder and rape and other offenses. He chose not to attend his seven-day jury trial, though, in hindsight, it wouldn't have mattered much.
Comer had the same chance at his trial as he'd allowed his victims at Apache Lake -- none.
His murder victim, Larry Pritchard, was a drifter whose fatal mistake was settling down for the night at the same campground as Comer. He died from a bullet fired at close range, after which Comer cut his throat.
The motive seems to have been a combination of robbery and an intense desire to kill.
Tracy Andrews was spending the evening with her boyfriend, Richard Brough, at a nearby campsite. Comer hog-tied Andrews to a vehicle, and forced Brough to watch as he raped her the first time.
Andrews made an especially compelling witness, telling a rapt jury how she'd later escaped Comer's clutches and fled into the wild.
It didn't help matters when she described how Comer had shot Pritchard's purebred beagle after murdering the man. (Comer has denied shooting the dog.)
His attorneys presented little by way of defense or mitigation. After the conviction on all counts, Judge Ronald Reinstein demanded Comer's presence at sentencing, a memorable event.
First, Maricopa County jailers rooted Comer from his cell with high-powered water hoses, truncheons and fists. Comer tried to stab them with a nine-inch-long shank during the clash. Finally, he was strapped to a wheelchair, and pushed into Reinstein's court.
Naked except for a towel draped over his genitals, he sat before Reinstein slumped and mute, his face bloodied from the jailhouse struggle, his body a mélange of indecipherable tattoos, the very image of a modern-day monster.
The judge sentenced Comer to death, and added more than 300 years on the rape-related convictions. Later that day, April 11, 1988, authorities delivered Comer to death row in Florence, then located on Cellblock 6 at the main prison complex.
It wasn't his first incarceration in a maximum-security institution.
Robert Charles Comer's mother wrote the following in her journal, shortly before giving birth to him in San Jose, California.
"I feel that it will be a boy because only a boy can kick like this baby," Patricia Comer wrote on November 29, 1956.
Comer's history of violence and crime is told in thousands of pages of legal documents, psychiatric reports and other paperwork that have become public record over the years. Still, it remains something of a puzzle how Comer evolved from a personable kid who finished one badge short of being an Eagle Scout into a stone-cold killer.
He was raised in a middle-class family, the oldest of Patricia and Charles Comer's four children, all boys. His father was an engineer for a technology firm, and his mother worked as a quality-control inspector in Silicon Valley.
Photos of a youthful Comer depict a good-looking kid with an impish -- some might say devilish -- grin. He loved to fish and was a member of the school safety patrol, and played football for a time.
Comer's journey to death row started when he was detained as a juvenile in the early 1970s on charges of assault, burglary and trespassing. He quit high school during his senior year, and enlisted in the U.S. Army in January 1975. (Comer later earned his diploma by passing a GED test.)
He was training to become a military policeman when his past caught up with him. In July 1975, Army officials issued the 18-year-old an honorable discharge after learning of his juvenile record. The next year, Comer served four months in a California youth facility on a burglary rap, during which he became a member of an offshoot of the Aryan Brotherhood.
After that, his crimes escalated. In December 1978, police arrested Comer on charges of kidnapping, rape, assault with a deadly weapon, and other counts. He plea-bargained to a relatively soft prison term of seven years, and was sent for the first time to an adult prison.