9:02 a.m., March 8 Episcopal School's marketing director releases a statement about why Shane Schumerth was fired

The fired Spanish teacher who killed Episcopal School of Jacksonville head Dale Regan on Tuesday brought with him nearly 100 rounds of ammunition for an AK-47 assault rifle he purchased at a Jacksonville gun show early last month, a police source familiar with the investigation said Wednesday.

It's unlikely anyone will ever know why Shane Schumerth chose Regan as his only target, shooting her as many as 10 times before killing himself, the source said. Investigators have yet to find a note or other indication as to Schumerth's motive, said the source, who has not been authorized to speak publicly about the case.

Victim advocates meeting for a regular session of the Mayor's Victim Assistance Advisory Council on Wednesday got a sense of the dangers posed by the attack when board member Tom Hackney, chief of detectives with the Sheriff's Office, joined in a brief discussion about the shooting.

Related: AK-47, like the one used, a 'quite common' product

Related: Officials: Nearly impossible to prevent school shootings like Episcopal murder-suicide

"It had a very strong potential to be much worse," said Hackney, who gave no details about the case and didn't elaborate.

Schumerth's father said his family shares Northeast Florida's grief over the loss.

"We are in shock and grieve for the loss of our son, and for the family, friends and acquaintances of Headmaster Dale Regan," Steve Schumerth of Culver, Ind., said in an email. "Our prayers go up for them and the entire Episcopal School family. We are deeply sorry this happened."

A steady stream of mourners visited the school's campus, leaving flowers outside the entrance to remember Regan and sharing their grief.

Though the campus is closed until March 19, the school was open Wednesday for grief counseling and for meetings between students and teachers.

Sean Halloran and Anna Blake, both 15, said the moments together helped as they begin to deal with the shooting, when Schumerth entered the office with the assault rifle in a guitar case and killed Regan, then himself.

"I think it helps the teachers, too," Sean said. "Today is bringing the school together."

Parents are struggling, too, to figure out how best to guide their kids through the pain and fear. Shefali Vashi, whose daughter is in seventh grade, said the reality of it hasn't set in yet as her daughter laid flowers at the growing memorial.

At first, when she got the email from her homeroom teacher about gathering at the school, her daughter didn't want to come back to the building where Regan was killed. But Vashi reminded her that seeing teachers she cares about might make them both feel better.

"She's keeping to herself, so I'm trying to keep her talking about it, asking questions," Vashi said.

For Jane Goodwin, whose daughter Casey is also in seventh grade, the school's response to the tragedy has reinforced that Episcopal is a good place for Casey.

"They kept us updated, and all kinds of faculty have been available to help our kids," Goodwin said. "It is shocking, but I have no reservations about how it was handled."

Justin DiFilippo, 15, and his brother Trenton, 12, stopped at the memorial to say a prayer for the woman whose smile they said they'll never forget. Justin was in the gym when the shooting happened, close enough to hear the pop of the gunshots.

"She touched so many people, in more ways than you can imagine," he said of Regan.

Their father, Tony DiFilippo, said Regan remembered something about each of his sons, including his older son in college, despite having known thousands of students through her career. She attended every single senior night for graduating student athletes, he said, and every hug she gave was meaningful.

"She just cannot be replaced," he said.

About 75 people gathered at All Saints Episcopal Church on Wednesday night to celebrate Regan's life and pray for the students, faculty and staff of the school many described as "a big family." They hugged each other while seated in the pews during the service and later stood outside in small groups sharing memories of Regan and the school.

Ann and Hal Wills said their son and daughter attended the school in the early 1970s. The couple knew Regan but said they also came to the service to show support for the school.

"The school is like one of our family," Ann Wills said. "We love the school and all the teachers and students there. It's one big family, our family."

Times-Union writer Teresa Stepzinski contributed to this report.

kate.howard@jacksonville.com, (904) 359-4697

jim.schoettler@jacksonville.com, (904) 359-4385