ROCKLAND — A 37-year-old South Thomaston woman accused of beating and strangling 83-year-old Helen Carver inside her home in February pleaded not guilty to murder and theft charges on Tuesday morning.

Sarah Richards will remain held without bail at the Knox County Jail in Rockland. She was arrested a day after Carver’s death on Feb. 21, and was indicted March 5.

The hearing Tuesday lasted less than 3 minutes in Knox County Superior Court before Justice Bruce Mallonee.

An affidavit filed by state police this year stated that Richards had stopped at the home of her ex-husband, either on Feb. 20 or Feb. 21 and asked him “if he would be willing to kill someone.”

The man told police he thought she was kidding. But after he learned about Carver’s death, he had no doubt that Richards was asking him if he would be willing to take part in killing Carver.

Carver’s son, Robert Carver, had talked with his mother by telephone shortly before 11 a.m. Feb. 21, and in the conversation she told her son that Richards had stolen her debit card. The Knox County Sheriff’s Office confirmed that the Owls Head woman contacted the office Feb. 14 about the theft.

A Knox County deputy had contacted Richards and was scheduled to interview her Feb. 22.

Witness reports determined that Richards and her boyfriend were seen leaving the area of Carver’s home at about 11:30 a.m. Feb. 21, the police affidavit states.

Carver’s son found his mother dead in the home shortly after 1 p.m. Feb. 21, after he was unable to reach her again by phone.

Richards initially told police that she had been at the house to shovel snow and went inside and Carver was in good shape when she left, according to the affidavit. However, she later changed her story and said she went inside and Carver was already dead. Richards said she provided life-saving efforts and left, according to police.

Richards then said when she went inside the house, Carver was upset over the stolen debit card and that the elderly woman “came at her.” Richards said she then lunged  at Carver and tackled her into an entertainment center. Richards also admitted to striking Carver in the head with a tool. The type of tool is not stated in the police report, but police obtained a warrant from the court to examine a shovel that Richards owned for any signs of blood.

Richards said she put her hands around Carver’s neck to determine if she had a pulse.

The affidavit states that the Medical Examiner’s Office determined the cause of death as blunt force trauma with signs of strangulation.

The new affidavit said that phone records for Richards and her boyfriend, Jimmy Wellman, could help develop a timeline of events leading up to the murder. The telephones were seized on the morning of Feb. 22 from the truck that Richards and Wellman were in.

Murder carries a minimum mandatory sentence of 25 years in prison in Maine.

Richards has a long criminal record. She was convicted of stealing more than 100 lobster crates from Fox Island Lobster in Cushing in 2013. She had worked at the business.

She received a nine-month jail term in 2016 for unlawful trafficking in drugs. In June 2017, she was sentenced to 30 days in jail for violating her probation for the prior drug conviction.

She was charged with theft in 2012 by Waldoboro police. In 2013, she served seven days in jail for violating a condition of release.

In 2006, Richards was sentenced to five days in jail for violating probation for illegal importation of drugs. In 2004, she was sentenced to 48 hours in jail for theft there.

Helen Carver lived alone at the South Shore Drive home after her husband’s death.