Despite Mr. Harper-Mercer’s online interest in high-profile shootings and neighbors’ memories of him as an enthusiastic gun collector who frequently went target shooting with his mother, the gunman’s father told CNN he did not know his son owned guns.

Mr. Harper-Mercer’s parents divorced a decade ago, and he had lived with his mother. The father said he had not seen his son since he and his mother, Laurel Harper, moved to Oregon about two years ago, but said there was no “disharmony or any bitterness” between him and his son.

Adding a raw, personal voice to the debate over gun control in the wake of this latest mass shooting, he said the United States needed to tighten gun laws.

“It has to change,” he said. “How can it not? Even people that believe in the right to bear arms, what right do you have to take someone’s life?” He would not discuss his son’s mental health issues, deferring to the police investigation. “Obviously, someone who goes and kills nine people has to have some kind of issue,” he said.

Standing on his lawn, Mr. Mercer said the shooting had devastated his family. “But we’re not alone in this,” he said. “My heart goes out to all the families that were affected by this.”

His interview came on the same afternoon that relatives of one of the students wounded in his son’s rampage also stepped in front of the microphones, here outside the front doors of Mercy Medical Center in Roseburg.

Image Christopher Harper-Mercer Credit... Associated Press.

Bonnie Schaan, the mother of Cheyeanne Fitzgerald, said that her daughter had been shot in the back during the massacre in her classroom. Tears welled up in her eyes as she explained that a bullet had clipped her daughter’s lung and lodged in one of her kidneys, which had to be removed. Cheyeanne, 16, a nursing student, remains in intensive care.

Mr. Harper-Mercer asked the young woman about her religion, according to her aunt, Colleen Fitzgerald, but “she didn’t answer.” Instead, Cheyeanne played dead next to her friend, Anastasia Boylan, a student who was also shot. Ms. Schaan said that her daughter did not know Mr. Harper-Mercer. After hearing the news about the shooting on campus, Ms. Schaan said she texted her daughter and said, “I’m on my way to school.” Instead she went to the hospital.

Cheyeanne has begun to talk with her father about the ordeal, Ms. Schaan said. Now, even a chair being moved unsettles her. Her mother added, “She’s mentioned all the blood.”

Dr. Jason Gray, the chief medical officer at Mercy Medical Center, said only two victims were still in the hospital. One was in critical condition and the other in fair condition. They were expected to be released in two to five days.

The hospital treated seven victims in total, Dr. Gray said. Two were released Thursday, four went into surgery and one died in the emergency department. Three other people were being treated for wounds at PeaceHealth Sacred Heart Medical Center at RiverBend in the town of Springfield.

On Friday, about 300 people showed up at Mercy Medical Center to donate blood, Dr. Gray said. The hospital set up a donation station nearby to handle the crowd.