A sign marks the entrance to the Wake Robin retirement community, Wednesday, Nov. 29, 2017, in Shelburne, Vt. Vermont State Police and FBI said they were investigating the source of the deadly toxin ricin that was found at the retirement community. A Wake Robin spokeswoman said residents were safe. (AP Photo/Lisa Rathke)
A sign marks the entrance to the Wake Robin retirement community, Wednesday, Nov. 29, 2017, in Shelburne, Vt. Vermont State Police and FBI said they were investigating the source of the deadly toxin ricin that was found at the retirement community. A Wake Robin spokeswoman said residents were safe. (AP Photo/Lisa Rathke) Credit: Lisa Rathke

Burlington — A woman is facing a federal complaint after investigators discovered the poison ricin in her home at a Shelburne, Vt., retirement community on Monday.

Betty Miller, 70, who lived at Wake Robin, is being held at the Chittenden Regional Correctional Facility after an initial appearance in U.S. District court Friday afternoon. Prosecutors are seeking to charge her with knowingly possessing an unregistered biological agent. The charge carries a maximum penalty of five years in jail.

FBI investigators said she used instructions printed from the internet to make ricin, an extremely toxic poison, out of castor beans picked from Wake Robin, according to court documents.

Miller allegedly told investigators that she attempted to poison other Wake Robin residents using the homemade ricin. The woman told an FBI agent she was hoping to test its effectiveness on the other residents by placing it on food or in beverages she expected them to consume on at least three occasions in the past several weeks, the documents show.

The agent said Miller “indicated her goal was to injure herself,” but that she first wanted to test the ricin on others.

State health officials say no one is currently ill with ricin poisoning, but that their investigation has revealed one Wake Robin resident reported becoming ill recently.

“No one is ill with ricin poisoning, and the danger for those who could have been exposed is over,” said Ben Truman, a Vermont Health Department spokesman.

It’s unclear if the illness discovered in their investigation was actually the result of ricin poisoning. No other cases of ricin poisoning have been discovered or reported in recent weeks through Vermont’s illness surveillance system or by emergency responders, Truman said.

Symptoms of ricin exposure typically occur within four to 10 hours and can include difficulty breathing, fever, cough, nausea, heavy sweating and tightness in the chest. Respiratory failure can result from inhalation of ricin. Ingestion of the poison causes vomiting, bloody diarrhea and hallucinations, according to health officials.

Emergency responders wearing full protective gear recovered half a tablespoon of ricin and some castor beans in a basket stored in a kitchen cabinet above Miller’s stove. In total, investigators said they believe she picked 30 to 40 castor beans and made two to three tablespoons of ricin following the online instructions.

The Health Department said on Wednesday that its laboratory had confirmed the substance discovered in Miller’s home was ricin. According to the FBI, Miller had a bottle labeled “ricin.”

Truman said department officials continue to work closely with Wake Robin administrators to ensure the health and safety of residents. Health Commissioner Dr. Mark Levine met with staff and residents to discuss the situation and answer questions, he said.

In a statement, Wake Robin CEO Patrick McKee called the situation an “isolated incident,” and said the the toxic substance was contained without having to evacuate any other residents. McKee’s statement said Miller would not return to the retirement community.

“The safety and security of Wake Robin residents and staff are always our highest priority,” McKee said, thanking authorities, his staff and residents for their handling of the situation.

Miller entered the federal courthouse in shackles on Friday, escorted by U.S. Marshals. A woman of average build with short-cropped white hair, she walked with a pronounced limp and her speech was slightly slurred when responding to questions from U.S. Magistrate Judge John Conroy.

Conroy said Miller had a history of mental illness.

First Assistant U.S. Attorney Eugenia Cowles asked for a three-day extension to further investigate in order to argue for Miller to remain in custody pending trial.

Cowles said that given the serious nature of Miller’s alleged crime, and the threat of a federal criminal charge, there is a risk she might attempt to harm potential witnesses, such as fellow residents or family who might have evidence against her.

In a detention motion, prosecutors wrote that Miller’s crime was “carefully planned,” and she had other substances in her home, besides the castor beans, which could be used to make plant-based toxins. They argue that no conditions of release will ensure Miller doesn’t harm herself or others.

“While she has indicated her ultimate intent was to hurt herself, she demonstrated a callous disregard for the lives of others in the process,” they write.

Miller was represented on Friday by federal public defender David McColgin, who did not object to the three-day extension. Conroy said Miller does not financially qualify for a public defender and will need to hire a private attorney.

Conroy scheduled a hearing for Wednesday on whether probable cause exists for the charge and to hear any arguments on the state’s motion for pretrial detention.

Miller’s son was in the gallery but declined to comment. He sat with criminal defense attorney Paul Volk, and the two discussed the case against his mother.

Asked if he would be representing Miller, Volk said, “We’ll see,” but declined further comment.