MADISON — Unanswered questions remain about a fatal shooting at a Madison, Wisconsin, private school Monday as new details emerge about the upbringing of the teenage girl who allegedly opened fire.

Investigators are working to piece together how and why 15-year-old Natalie Rupnow, who went by the name “Samantha,” allegedly committed the act that left one teacher and a student dead and wounded six others at Abundant Life Christian School, one week before Christmas.

Erin Michelle West, 42, of DeForest, and Rubi Patricia Vergara, 14, of Madison, were both pronounced dead at the scene of the shooting, the Dane County Medical Examiner’s Office said in a news release Wednesday.

Four people remain hospitalized as of Wednesday afternoon, according to hospital officials. Two are in critical condition, while the other two are in stable condition, officials told CNN.

The shooter appears to have died of a self-inflicted gunshot wound, according to Madison Police Chief Shon Barnes. She was pronounced dead at a local hospital Monday as a result of “firearm related trauma,” the medical examiner’s office said, noting additional testing is underway.

Barnes said Tuesday identifying Rupnow’s motive is a top priority and that it appears to be a “combination of factors,” but declined to provide more information.

Rupnow’s parents are cooperating with police, Barnes said, as more details about the teen’s home life come to light. Court documents show Rupnow’s parents have been married to each other and divorced from each other twice, with court orders requiring the teen to split time between her mother’s home and her father’s, according to court records obtained by CNN Wednesday.

It’s unclear whether Rupnow’s parents owned or possessed the gun used in the shooting, Barnes told CNN. Police, along with the district attorney’s office, will “want to look at if the parents may have been negligent,” he said.

Rupnow’s parents – Jeff and Mellissa Rupnow – have not responded to CNN’s repeated requests for comment.

Police are also talking to students to determine whether bullying was one of the factors, he said, and investigators are looking through the online presence of the shooter to try to learn new information.

Mackynzie Wilson, a sophomore at the school who had a locker next to Rupnow’s, said she never thought the student she described as shy would be capable of carrying out an act of such violence.

“She was really quiet. She didn’t really have any friends, and she just seemed really lonely,” Wilson told CNN. “It wasn’t like she was trying to fit in. She seemed very content being alone.”

The tragic deaths of a student and teacher at Abundant Life Christian School shook the tightly connected school community. The school – which many alumni’s children and grandchildren attend – is now grieving the losses.

Students described West, a teacher at the school, as a loving person who devoted her time to supporting them.

Angel Brube, a seventh grader at the school, told CNN he knew the teacher well and described her as “always very kind and caring” and “a really good person.”

“She was also very friendly and communicative,” Brube said.

Wilson, the sophomore, said losing her teacher “really hurt.”

“She really loved her kids, and she really, really loved everyone at our school, and she would have done anything for them,” Wilson said.

Vergara, a freshman at the school, was an animal lover who was passionate about art, reading and playing music, according to her online obituary at Gunderson Funeral Home.

“She was an avid reader, loved art, singing and playing keyboard in the family worship band,” her obituary reads. “She shared a special bond with her beloved pets, Ginger (cat) and Coco (dog).”

Her funeral service will be held on Saturday morning in Madison, according to the obituary. Vergara is survived by her parents and brother.

West and Vergara died of “homicidal firearm related trauma,” preliminary autopsy results found. The medical examiner’s office said it will be conducting additional testing.

“They’re integrated into our lives, and they will be forever remembered,” Wilson’s mother Lyndsay O’Connor, an alumnus of the school, told CNN.

For the faculty and staff at Abundant Life, healing will not happen quickly.

Wilson was in her composition class when she heard five loud bangs – two classrooms away from where the shooting happened. Some students in her class joked about the noises being gunshots. But Wilson soon realized it wasn’t a joke.

“Active shooter, this is not a drill,” the principal announced before another gunshot rang out and students sat on the floor, holding each other and crying.

“I didn’t know if I was going to live or not because you don’t know who (the shooter) is. You don’t know what they’re capable of. I didn’t know if it was someone from our school or not,” Wilson said.

Police arrived a few minutes later, and Wilson left the building with her hands up, crying and shaking, she recalled.

Two days later, Wilson said she’s still in shock but is “just trying to heal and move on” by leaning on the community for support.

Wisconsin State Assemblyperson Jerry O’Connor, whose great-niece and nephew go to Abundant Life, said, “I think it’s going to be a little bit of time as they reflect back on what happened.”

“My nephew could hear bodies hitting the floor. My niece, across the hall, could hear gunshots,” O’Connor told CNN Wednesday.

O’Connor’s brother-in-law is a basketball and golf coach at the school, and another relative is the school’s principal, he said.

“I was sitting in a restaurant in Nashville on Monday morning, and I looked at a news headline and it said, ‘There have been shootings at Abundant Life Christian school,’” O’Connor said. “It’s pretty distressing for anyone that’s associated with that school.”

Hundreds gathered outside the Wisconsin State Capitol on Tuesday night to remember victims.

A Christmas tree decorated for the holiday season twinkled as mourners gathered in freezing temperatures to grieve, holding candles and hugging therapy dogs.

For students like Wilson, it was difficult returning to the school for the vigil because of the “fear and trauma that built up,” she said.

Madison local Justin Myers brought his two young children to the Tuesday vigil, telling CNN he had “told them the truth” about what happened at Abundant Life.

Although his kids do not attend the Christian private school, he said they were ordered to go through a secure protocol at their nearby public school on Monday, what the father of two described as a shooting drill.

“It’s an epidemic, and I’m not a big believer in the thoughts and prayers crap –– I don’t think it works,” he added. “We need action, legislation and laws to make sure that guns don’t get into the hands of people who don’t have them.”

Nicole Hockley, the co-founder and co-CEO of Sandy Hook Promise, whose child was killed in the Sandy Hook shooting in 2012, said in a statement following the shooting at Abundant Life that “we must work together to protect our families and communities from gun violence.”

President Joe Biden, Vice President Kamala Harris and Wisconsin Democratic Rep. Mark Pocan called for more action from Congress to address gun violence.

“From Newtown to Uvalde, Parkland to Madison, to so many other shootings that don’t receive attention – it is unacceptable that we are unable to protect our children from this scourge of gun violence,” Biden said in a statement Monday.

In an interview with CNN, Pocan said: “I’ve sat through so many moments of silence on the floors of Congress that are followed by zero moments of action.”

Existing Wisconsin law limiting gun access to children is not sufficient, Dane County Executive Melissa Agard said Tuesday.

“Our laws in Wisconsin are far too lax when it comes to access of guns by children,” Agard said Tuesday.

“We should have background checks. We should have red flag bills, we should be providing adequate support for everyone in our community when it comes to behavioral health,” Agard added. “People should not be waiting when they raise their hand and ask for help.”

Both federal and Wisconsin law generally make it illegal for someone younger than 18 to possess a firearm. State law similarly makes it illegal for any person to intentionally sell, loan or give a dangerous weapon to someone younger than 18 –– but there are exceptions such as allowing minors to possess a firearm for target practice under adult supervision, for use in the armed forces or for hunting.

Someone who intentionally sells, loans or gives a dangerous weapon to a person under 18 can face up to three and a half years in prison, according to Wisconsin law. If the minor uses a dangerous weapon and causes death to themselves or another person, violators can face up to six years in prison.

Wisconsin also has a child access firearm law that makes it illegal to recklessly store a loaded firearm within reach or easy access of a child younger than 14.

Anyone who recklessly stores or leaves a loaded firearm within the reach or easy access of a child can face up to nine months in prison if that child takes the firearm without permission and if the child uses the gun and “causes bodily harm or death to himself, herself or another.”

Prosecutors in recent years have taken steps to hold parents accountable for providing their children with firearms they would go on to use in school shootings. Two such cases include school shootings at an Oxford, Michigan high school in 2021 and a Winder, Georgia high school in September. — CNN