Bob Holmes, who with his wife Arlene has attended the proceedings on the outskirts of Denver almost every day since they began in late April, made his long-anticipated appearance on the witness stand during the trial's punishment phase. Arlene Holmes is expected to testify on Wednesday.
The Holmes family lives near San Diego, California, and James had moved to Aurora, a Denver suburb, for graduate school.
On July 16, the jury found the now 27-year-old guilty on all counts related to the attack in which he killed 12 people and wounded 70. The panel of nine women and three men must now decide whether the former neuroscience graduate student will be executed or serve life with no parole.
Bob Holmes, a statistician, said he and his wife had no idea their son was suffering from mental illness before the massacre. They did know he split up with his girlfriend and that he dropped out of graduate school.
"I assumed he might be depressed. That was our main concern," the shooter's father said, adding they had made plans to see their son.
Displaying photos of family gatherings and camping trips, and home movies of the defendant as a child surrounded by relatives, defense attorney Tamara Brady asked Bob Holmes if he still loved him.
The gunman's father replied that he did.
"Why?" Brady asked.
"Well, he's my son, and we always got along pretty well, and he was actually a really excellent kid," Bob Holmes said.
He added that he first learned of the mass shooting via a phone call in the middle of the night from a journalist.
He said he initially believed his son must have been one of the victims. But before long, police, FBI agents and members of the media turned up at the family's front door.
"It never occurred to me that he might be the shooter," Holmes' father said.
They later got to see their son in jail.
"He was clearly really messed up," he told the court. "He was able to talk to us, which was good, and he told us he loved us ... But I could see something was really wrong with him."
SISTER STILL LOVES HIM
Holmes opened fire with a semiautomatic rifle, shotgun and pistol inside a theater packed with 400 people watching a midnight screening of a Batman film. Before leaving for the multiplex in Aurora, he booby-trapped his apartment with explosives. He also donned a helmet, body armor and gas mask.
On Monday, the gunman's younger sister broke down and sobbed as she became the first of his relatives to testify at the trial, telling jurors her brother's murders were completely out of character and that she still loves him.
Last week, the jury found the prosecution had proved "aggravating factors" which, the state argued, made Holmes' crimes especially heinous and deserving of execution.
Defense attorneys are now calling witnesses in hopes they can prove mitigating factors outweigh the aggravating ones.