The Vermont woman who police say shot and killed a social worker because she was upset about losing custody of her 9-year-old daughter pleaded not guilty to a first-degree murder charge on Monday.

Jody Herring entered a not guilty plea and was ordered held without bail. She was arrested Friday following the death of Lara Sobel who police say was shot twice in the head as she came of the Barre office building that houses the regional office of the state Department for Children and Families.

According to court documents, Herring, 40, was "very calm and laughing" after shooting and killing Sobel with a .270 caliber rifle. A state prosecutor reportedly wrestled the rifle away from Herring after the shooting and helped detain her until police arrived.

Court paperwork said Herring became agitated when police interviewed her on Friday night. She said police never helped her when her boyfriend beat her and she complained about the injustices done to her by DCF.

Police believe that before shooting Sobel, 48, Herring shot and killed two cousins and an aunt in the adjoining town of Berlin. But no charges have been filed yet in connection with the deaths of Regina Herring, 43, and Rhonda Herring, 48, the suspect's cousins, and Julianne Falzarano, 73, an aunt.

On Sunday, about 300 people packed into Barre's Old Labor Hall Sunday to pay tribute to Sobel before marching to the parking lot where Sobel was shot.

"Lara was a beautiful, beautiful individual and she really, really cared about the kids, all the kids," Joseph Faryniarz, a cousin of Sobel's husband, said during the vigil. "This is a tragedy and the family is doing the best that it can."

The Burlington Free Press reported that Tiffany Herring, 23, who identified herself as the daughter of one of the victims, said her mother received a threatening phone call from Jody Herring on Friday morning.

"My mother got a call in the morning, maybe 7:30 or 8 o'clock, saying it was Jody Herring saying, 'You guys need to stop calling DCF unless you guys are going to have it coming to you,'" Tiffany Herring told the newspaper.

She said she discovered the women's bodies.

"Both doors were wide open, and I walked into the living room, and that's where I saw my mom dead," she said.

Barre Police Chief Tim Bombardier said the weapon used to kill Sobel was a hunting rifle, but he would not reveal the caliber or additional details about it. He also would not comment on whether Jody Herring had obtained the gun legitimately or what may have triggered her to act Friday — weeks after losing custody of her daughter.

"That's one of those things that's open to interpretation, so I'm going to stay away from it," Bombardier told The Associated Press.

He also would not discuss the 9-year-old's father or his whereabouts. Officials said after Sobel's shooting that the girl remained in state custody.

On Sunday, the governor's office distributed a statement to state employees saying all offices would be open on Monday, but state officials were reviewing security at state buildings.

Paul Coates, a lifelong Montpelier resident, said before the vigil that he knew Sobel, the other shooting victims and the woman accused in the shooting.

"It's just tragic, it's just sad. I am sick about it, it just didn't need to happen," Coates said.

Cindy Walcott, DCF deputy commissioner, said that over the weekend, she has been thinking there would be no way to go forward, but she found support from the people she and the other social workers have helped overcome obstacles.

"In my darkest moments I actually have focused on the children and families that we serve and I think about the dark moments that they've had in their lives and how so many of those have triumphed over those (situations) and learned from them and moved forward," Walcott said.

Court documents describing Jody Herring's criminal background listed her as being "Brady Disqualified," meaning she was unable to legally purchase a firearm because of past criminal convictions. Her criminal history includes drug charges, assault, disorderly conduct, and other offenses, the documents show. Herring had 11 misdemeanor convictions, according to the documents.

Investigators will be looking into how Herring obtained the hunting rifle she allegedly used to kill Lara Sobel. Court documents show police found a receipt from early June for ammunition for a rifle. It is unclear if Herring already owned a weapon before her "Brady Disqualification," or if she had access to one through some other means.

Attorney General Bill Sorrell, D-Vermont, said it is possible gun charges may be levied later, but he said right now, police and his office are prioritizing the homicide cases and the ongoing investigation into the deaths of Hereing's relatives.

Gov. Peter Shumlin, D-Vermont, urged Vermonters to speak respectfully of DCF workers following the tragedy. He said for quite some time, in online message boards and other forums, people have bashed the performance of DCF, while Shumlin said the employees are often doing challenging and "heroic" work.

The harsh criticism Shumlin described followed the deaths of Dezirae Sheldon and Peighton Geraw, small children who died allegedly at the hands of abusive parents. Both had were the subjects of investigations or other encounters with DCF workers prior to their deaths. No criminal wrongdoing was found by DCF in those cases, but the state has added social workers to reduce the caseload burden on employees.

"And I think we have to remember that hateful language breeds, fertilizes hateful acts," Gov. Shumlin said of the tone he has seen some people use describing DCF employees. "And we all have to work together to appreciate the work that these hard-working state employees are doing with our most vulnerable kids."

Ken Schatz, Vermont's DCF commissioner, said members of his department are receiving help including the offer of grief counseling by Washington County Mental Health. In the meantime, he said the difficult work of DCF continues.

"They are continuing their work," Schatz said of his department's employees. "They are mindful that we do need to continue to provide this assistance and support to children and families, so they're not backing away. At the same time, they are definitely hurt."

"A lot of us are pretty scared still," said Jill Remick of the Vermont Agency of Education, who works in the same building as Lara Sobel did, and who said she heard the gunshots. "We can talk about how we can maybe make security better but I'm not sure anything could have been done to stop this person from doing what she did. But we want to try. And we want to try to make it as easy as possible for DCF workers to do the job they do."

Gov. Peter Shumlin spoke Monday with close members of the family of Regina and Rhonda Herring, and their mother, Julie Ann Falzarano, according to Shumlin's office. At the family’s request, the Governor asked the media to respect the privacy of the Herrings.

In addition, members of the Herring family urged people to avoid social media fundraising sites alleging to pay for funerals or any other purpose connected to the tragedy, Gov. Shumlin's office said. No legitimate fund-raising sites have been established at this time, according to a news release the office sent necn.