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Thirty-eight years after a baby who was found dead in a ditch was buried, Sioux Falls police have made an arrest in the case.

Theresa Rose Bentaas, 57, was arrested Friday morning around 7:15 a.m. after police determined through DNA that she was the mother of Baby Andrew, retired detective Mike Webb said.

The case transfixed the city for decades. The baby was alive when he was placed in a ditch in a cornfield at 33rd Street and Sycamore Avenue in what was then rural Sioux Falls and "slowly succumbed to exposure."

Bentaas was charged Friday with murder in the first degree, murder in the second degree and manslaughter in the second degree, Webb said. She's being held on a $250,000 bond.

Police were able to acquire DNA from Andrew after exhuming the body 10 years ago. Through current genealogy sites, police were able to develop a family tree. More searches of birth records and marriage records led them to Bentaas, where a DNA sample provided through a search warrant determined she was the mother, Webb said.

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According to the affidavit, Bentaas said she was "young and stupid." She said she was pregnant in 1980-1981 and hid the pregnancy from friends and family.

Bentaas admitted to having the child in her apartment alone, then drove the baby to the place where he was later discovered. She chose it because of "proximity," according to the affidavit.

From the archives: Police hope DNA leads to parents of abandoned baby

Bentaas saw the coverage of Baby Andrew on the news but said that she "was in denial that she was the one responsible for that."

When asked if she thinks about it when she drives by the area now, she stated, "of course,'" the affidavit wrote.

Webb said the father of Andrew, Dirk Bentaas, is not facing charges in the case. The couple has two living adult children.

Baby Andrew:What we know about Theresa Bentaas

Timeline:How police spent 38 years trying to solve Baby Andrew's murder

"I couldn't be more pleased with the results today and the arrest and the closure that we find, as well as the hard work and dedication for the pursuit of justice for Andrew," Chief Matt Burns said.

In most cases, Webb said he can assure family members of the victim that he's been working on the case and that he'll find a resolution, or a way to relieve their burden. This case was different, since the family was the person who committed the crime.

But Webb said there was still justice for Baby Andrew.

"I think his voice was heard," Webb said.

How the case was solved

Police recently connected the DNA from Baby Andrew and a distant relative who used a DNA-based genealogy product to connect his death to Bentaas.

Webb opened the case in the spring of 2009 and exhumed Baby Andrew's body in September of 2009 to extract DNA from his bones and tissue. Baby Andrew's remains were sent to a lab at the North Texas University Science Center.

His body was re-interred in June of 2010.

After the DNA profile didn't have any matches in the South Dakota DNA database, Webb turned to Parabon Nanolabs Inc. The private genealogy company found possible genetic family matches and Webb's team created a family tree that led to Bentaas as the mother.

Detective Patrick Mertes went to the Bentaas' house and conducted a "trash pull," where he used beer and water containers and cigarette butts to use as evidence and extract DNA. The items were sent to the South Dakota Forensic Lab for testing.

Related: Bentaas murder case to be prosecuted under 1981 laws

During a police interview on Feb. 27, 2019, Dirk admitted he saw Theresa "had a bump and then no bump" around the time Baby Andrew was found.

"(Dirk) Bentaas admitted to hearing about (Baby Andrew) being found but did not believe the defendant was capable of doing such an act," the affidavit read.

Webb said he received confirmation that Dirk and Theresa were the father and mother of the baby on Monday.

Case haunted city for decades

Baby Andrew’s murder has perplexed police and haunted certain residents for decades.

It’s tormented the man who found the lifeless child, with tears frozen to his cheeks, and who still visits the child’s grave.

A red wine-colored blanket caught the eye of Lee Litz while cruising in the passenger seat of a friend’s new jeep on Feb. 28, 1981.

Litz asked his friend to pull over to pick up the blanket lying in a ditch near 33rd Street and Sycamore Avenue, and he found the lifeless newborn swaddled inside.

The newborn still had the placenta attached, and laying next to the baby was a pair of women's underwear, a shirt and Klennex-type material with blood on them, according to the affidavit.

A witness interviewed at the time described a light-colored Datsun-style vehicle parked in the area with "a woman's legs hanging out and some blankets on the ground at the time."

In the moment, Litz knew the baby was dead but he still thought paramedics might revive him. He rushed to a friend’s house nearby and called police.

Baby Andrew would be the same age as Litz’s daughter. He wondered what Baby Andrew would have become if he’d noticed him lying in the ditch sooner.

“I sure would have adopted him rather than see him die like that,” Litz said in an interview with the Argus Leader in 2017.

Litz still visits the baby's grave at St. Michael Cemetery on Cliff Avenue. So does Litz’s daughter, Crystal Oestreich, who leave flowers and sock animals for someone she considers her older brother.

Two days after the funeral, Litz recalled hearing about a baby who was dropped off in front of a local fire station. He regretted that Baby Andrew didn’t have the same chance.

“To see a child thrown away like that – how could someone do that,” said Litz. “Someone got away with murder.”

Dozens gathered for funeral

Baby Andrew was laid to rest at St. Michael’s Cemetery on Cliff Avenue, the secrets of his death buried with him for 38 years.

Police attempted to link the baby’s DNA to potential parents in 2017, but the effort was fruitless. Police released new crime scene photos of Baby Andrew’s discovery in 2018, hoping someone would come forward and identify Baby Andrew’s parents.

About 50 people attended Baby Andrew’s funeral more than a week after he was found.

Children left stuffed animals next to the tiny casket, and a gold-plated pin was fastened to his yellow pajamas reading simply, “You are loved.”

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