A teacher and three high school graduates were among those shot dead at Oregon community college by a gunman armed with three pistols and a rifle, as well as five additional magazines.
Police released brief details of the nine people killed in the shock attack, who range in age from 18 to 67 and include three 18-year-olds.
Nine people are still being treated for injuries they suffered when Chris Harper-Mercer, whose father is reportedly English, opened fire at Umpqua Community College in Oregon on Thursday before dying in a shoot-out with police.
President Barack Obama is ordering that American flags be flown at half-mast in honour of the victims of the mass shooting at the college in Roseburg.
The authorities have identified the nine victims as 19-year-old Lucero Alcaraz, of Roseburg; 18-year-old Quinn Glen Cooper, of Roseburg; 59-year-old Kim Saltmarsh Dietz, of Roseburg; 18-year-old Lucas Eibel, of Roseburg; 67-year-old teacher Lawrence Levine, of Glide; 33-year-old Jason Dale Johnson, of Winston; 18-year-old Rebecka Ann Carnes, of Myrtle Creek; 44-year-old Sarena Dawn Moore, of Myrtle Creek; and 20-year-old Treven Taylor Anspach, of Sutherlin.
Mr Cooper, who was in his fourth day of college when he was shot, was described as "sweet and compassionate" in a family statement read out by police.
A statement from the family of Mr Johnson said he was "proud of himself" to have recently enrolled in college and had "finally found his path".
Mr Eibel had begun studyingchemistry and volunteered at a wildlife centre and animal shelter.
Two victims, including Trevor Anspach who was described as "larger than life", were part of the "immediate fire family", the local fire service said.
Harper-Mercer apparently demanded to know his victims' religious beliefs before opening fire at the campus.
Authorities investigating the massacre said six weapons were recovered from the college while a further seven were found during a search of his home.
Bureau of Alcohol, Tobacco, Firearms and Explosives spokeswoman Celinez Nunez said all of the weapons were purchased legally, seven of them by the shooter or his family members in the last three years.
Harper-Mercer is not thought to have had a criminal history. Investigators believe he may have been a student at the college because a receipt found at the scene showed he purchased textbooks from the campus bookshop two days before the shooting.
It has emerged that Harper-Mercer also failed basic training for the US Army in 2008 while his social media profiles featured content supporting the IRA.
The details of his weapons arsenal emerged as Oregon governor Kate Brown urged that the debates over America's gun laws wait, to allow the community to support grieving families.
Calling for action to prevent further "senseless violence", Ms Brown told reporters: "This is a conversation we will have but today is not the day."
US senator Ron Wyden, Oregon's senior senator, said: "As a country we cannot just shrug our shoulders and move on."
Harper-Mercer's father, Ian Mercer, told reporters he was "just as shocked as everybody else" at his son's actions.
Speaking with a distinctive English accent from his home in the US, Mr Mercer told reporters: "It's been a devastating day, devastating for me and my family. Shocked is all I can say."
Carmen Nesnick, Harper-Mercer's stepsister, said he was born in the United Kingdom and travelled to the United States as a young boy.
She added: "I'm actually still shaking and my mom is in there crying. I don't know what to do."
Witnesses described the moment Harper-Mercer stormed the school.
Kortney Moore, 18, said she was in a writing class when a shot came through the window and hit the teacher in the head.
The gunfire, shortly after 10.30am local time, sparked panic as students ran for safety and police and ambulances rushed to the scene.
Hannah Miles, 19, said she was in her writing class when her teacher got a call from security saying the school was in lockdown. She heard gunshots from a neighbouring classroom.
She said that, huddled together in the locked classroom, the students and teacher heard footsteps outside and a man's voice call out to them: "Come on out, come on out." They remained quiet and did not open the door.
Police soon arrived and, after students were convinced that they were indeed officers, they opened the door.
"It was like a huge burden had been lifted," she said. "A huge sigh of relief that we were going to be OK."