Story highlights The coroner's office says Leila Fowler died after suffering multiple stab wounds

Amid stepped up security, parents at her elementary school say they're afraid

School principal: "I don't think I ever saw Leila without a smile on her face"

The girl's brother "is not a suspect at this time," a sheriff's spokesman says

Sheriff's deputies on foot and in patrol cars made their presence known at a northern California school on Monday.

Amid the stepped up security, classmates at Jenny Lind Elementary School carried flowers for Leila Fowler. Their parents held onto fear.

"I'm scared for my kids, for the family," mother Wendy Converse said. "It's horrible."

Fowler, an 8-year-old third-grader at the school, was stabbed to death at her home over the weekend.

As police search for suspects, word of the killing has left many shaken in the community, which is about an hour outside of Sacramento.

"Leila was bubbly, she was vivacious, a great student. ... I don't think I ever saw Leila without a smile on her face," Amy Hasselwander, the school's principal, told CNN affiliate KCRA . "Just a bright girl, just kind, compassionate, sincere to everyone."

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Converse said her son, Elijah, was friends with Leila.

"They sit together at school. It's very sad," she said. "Things like that don't happen here."

The girl died of shock and hemorrhages caused by multiple stab wounds, the Calaveras County Coroner's Office said on Monday.

Her mother said the family was still coming to grips with their loss.

"We are devastated," Crystal Walters, Leila's mother, told CNN via Facebook correspondence early Monday. "She didn't deserve this. ... She was so full of life."

No suspect named

Police say Leila and her brother were home alone on Saturday when he saw an intruder leaving the house.

He then found his sister stabbed and severely wounded. She died minutes after arriving at the hospital, authorities said.

Since then, police have been running down leads but say they have no specific suspect.

"We're searching extensively into attics and storage sheds. It is a difficult area to search -- it is rural, remote and the grass is tall right now," Calaveras County Sheriff's Capt. Jim Macedo said.

Authorities have combed the home and the neighborhood for evidence.

"We did collect fingerprints during that search," Macedo said, "and we did collect what we believe to be DNA. Those prints and DNA will hopefully be processed within the next week."

A neighborhood on edge

Word of the killing rattled many residents in the neighborhood.

Michael Range, who lives near the Fowlers, said he heard about Leila's deadly stabbing from a boy who lives nearby.

"I took my kids instantly and locked the doors," he said. "It was scary. We've been inside all weekend."

Ryan Wydner, who lives across the street from the Fowlers, said the girl's death left him feeling anxious.

"Anything's really possible at this point," he said. "What's the difference between that guy going left and right and coming into my house? I don't know."

While authorities said they had "no specific suspect," they are looking for a white or Hispanic male with a muscular build, about 6 feet tall, wearing a black long-sleeved shirt and blue pants. He is considered to be armed and dangerous, the Sheriff's Office said.

Macedo said the boy who found his sister "is not a suspect at this time, but we are continuing to talk to him, which would be normal because he was the last person with the child."

Detectives continue to track down dozens of leads phoned into a tip line created Saturday, including some leading to other counties, he said.

More than 100 members of the law enforcement community are working on this case, Macedo said.