A South Dakota woman was convicted on Friday in the death of her newborn son, according to court documents, ending a cold case that began when the boy’s body was found near a cornfield four decades ago.
The woman, Theresa Bentaas, 60, of Sioux Falls, entered an Alford plea, which allows defendants to enter a guilty plea without admitting to the crime, to first-degree manslaughter in an agreement with prosecutors in which they dismissed two murder charges, according to the Second Judicial Court in South Dakota.
Ms. Bentaas had previously pleaded not guilty to the three charges.
Lawyers for Ms. Bentaas declined to comment on Monday. The Minnehaha County State’s Attorney office did not immediately respond to a request for comment on Monday.
The charges against Ms. Bentaas drew from the discovery of an infant’s body on Feb. 28, 1981, when a driver near Sioux Falls spotted a pile of “wine-colored” blankets by the road, he said decades later in an interview with a local newspaper, The Argus Leader. The driver pulled over to look at the blankets because they looked new, he said.
Inside the bundle was a dead baby, and traces of blood were found on clothing nearby, according to the arrest affidavit for Ms. Bentaas.
An autopsy found that the baby had been born alive, most likely the day before, and had probably died of exposure, according to the affidavit.
Investigators were unable to find the baby’s mother and relatives. After about 50 residents attended the baby’s burial at St. Michael Catholic Cemetery, the case went cold. The baby became known as Andrew John Doe.
In 2009, as DNA analysis grew widely accessible and spread into criminal investigation, detectives picked up the Sioux Falls case and obtained a court order to exhume the body for testing. The remains were taken to the University of North Texas Health Science Center, where a DNA profile was obtained, according to the affidavit, which noted that the baby’s remains were reburied in 2010.
Through advanced DNA testing, a family tree was produced, leading investigators to a residence in Sioux Falls where Ms. Bentaas had been living, the affidavit said.
Detectives found DNA in the trash at her residence, and analysts determined that it “could not be excluded” from a profile of the baby’s biological mother, according to the affidavit.
In March 2019, the Sioux Falls Police Department announced that investigators had, through DNA testing and genealogy databases, finally tracked down the baby’s mother, naming Ms. Bentaas. She was arrested on murder charges.
On Feb. 27, 2019, Ms. Bentaas told investigators that in 1981 she was “young and stupid,” according to the affidavit. She said she had hidden her pregnancy from family and friends, and given birth alone in her apartment. She then drove the baby to the place by the road where he was later found, the affidavit said.
The affidavit said that Ms. Bentaas recalled feeling “sad” and “scared,” and that she continued to think of that night when she drove by the spot.
She is scheduled to be sentenced on Dec. 2, according to court records.
Susan Beachy contributed research.