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Sioux City mistrial won’t stop a family’s quest for justice in 1983 cold case

A group of people gathers in front of a makeshift memorial near a wooded area. There is a vintage picture in the middle with a lady with brown hair and glasses.
Sheila Brummer
/
Iowa Public Radio
Terri McCauley's nephew leads a gathering of family and supporters at a memorial near where Terri McCauley's body was found in 1983. The group gathered Monday after a mistrial was declared in the murder trial of Thomas Popp.

More than four decades after Terri McCauley was killed in Sioux City, her family and supporters sat in a Woodbury County courtroom waiting to hear whether jurors had reached a verdict in the trial of the man accused of her death.

Instead, Judge Tod Deck announced Monday that the jury remained deadlocked.

“The court finds that the jurors have deliberated until it satisfactorily appears that they cannot agree. The court is therefore declaring a mistrial,” Deck said.

Tears filled the courtroom as McCauley’s relatives and supporters absorbed the decision. One woman let out an ululation, a vocal expression sometimes used by Native Americans during times of mourning and grief, before being peacefully escorted from the room.

The 12 jurors had deliberated for more than 14 hours over three days in the first-degree murder case against 63-year-old Thomas Popp.

A man in a blue shirt is sitting in a courtroom in a wheelchair. His attorney is sitting to his right.
Sheila Brummer
/
Iowa Public Radio
Thomas Popp (front) sits next to his defense attorney Ben Mulford, who is running against incumbent Woodbury County Attorney James Loomis in the November election.

For McCauley’s family, the decision meant another wait for answers in a case that began in 1983.

McCauley, a member of the Omaha Tribe of Nebraska, was 18 years old and a young mother of two when she disappeared after a night out with friends on Sept. 27, 1983. A man walking his dog found her body several days later near what is now Trinity Heights. She had been shot in the face with a 20-gauge shotgun.

Popp had long been considered a suspect by Sioux City police. A grand jury indicted him in January 2025, and he was extradited from Washington state to stand trial.

A case built more than 4 decades later

Witnesses testified that McCauley told a friend she had a “date” the night she disappeared and was last seen getting into a small white car, similar to one driven by Popp.

Investigators said Popp came to their attention a few months after the killing, when officers responded to a report of a gun being fired at an apartment building where he lived, near the area where McCauley was found. Detectives discovered Popp owned two 20-gauge shotguns and ammunition consistent with the type used to murder McCauley.

The defense emphasized that prosecutors had no physical evidence, including DNA, tying Popp to the crime.

“Not one piece of hair, not one fingerprint, not one piece of fiber from the clothing Terri McCauley was wearing located in Mr. Popp’s vehicle,” defense attorney John Loos said during opening statements.

A Native American man talks to reporters in front of a law enforcement center. There are 5 people standing behind him.
Sheila Brummer
/
Iowa Public Radio
Family spokesperson Joshua Taylor speaks with reporters outside the Woodbury County Law Enforcement Center in Sioux City after a mistrial was declared. To his left is his father, Mike McCauley, Terri McCauley’s brother.

McCauley’s nephew, Joshua Taylor, said he hopes Woodbury County Attorney James Loomis will try the case again.

“We haven't lacked confidence in this county attorney's ability to move forward, and even more so now, I think the evidence that James presented is and was more than enough to render a guilty verdict,” Taylor said.

Loomis has 90 days to decide whether to retry Popp. If convicted, Popp would face a mandatory sentence of life in prison without parole.

A family still searching for justice

Taylor said the trial accomplished something his family had wanted for years; it brought renewed attention to his aunt and her life.

“Terri didn't have a voice for so long,” Taylor said. “And this past two weeks, her voice was loud. And that's because of James Loomis.”

After leaving the Woodbury County Law Enforcement Center, McCauley’s relatives and supporters gathered at a makeshift memorial along 33rd Street, near where her body was discovered.

Taylor burned sage and asked for strength as the family confronted another setback in the decades-old case.

082426_McCauley Memorial Video (1).mp4

“Help us understand why justice has to be delayed, understand why those jurors didn't see a beautiful young lady, a beautiful mother that was stolen from us,” Taylor said. “Father, we ask that you ease our minds. We're all struggling. Our hearts are struggling.”

McCauley’s son, Nate McCauley, said social media posts about the cold case and news coverage of the trial have introduced his mother to people far beyond Sioux City.

“These last couple of weeks, everybody's heard her name. Everybody's seen her face,” Nate McCauley said. “There are even people in China sharing her stuff too on RedNote. They know her story over there, too. I love that.”

A side view of people listening to court proceedings.
Sheila Brummer
/
Iowa Public Radio
Nate McCauley on the opening day of testimony in the murder trial of his mother, Terri McCauley, on Aug. 12.

Nate McCauley was very young when his mother died and wishes he could have known her. He shared with the group one memory of her that came to him in a dream.

“She was giving me a bath, and I was looking up at her," he said. "The Creator blessed me with that."

He asked those gathered to continue praying for the family.

Terri’s brother, Mike McCauley, remembers his sister as someone who loved having fun and babysitting children. He shared that Terri had just begun learning more about her ancestors and cultural traditions before her death.

“When that happened, the book closed,” Mike McCauley said. “But we're reopening it now. Our family, especially my kids, have asked so many times who took Terri's life. They got to see the individual.”

He said the family still intends to seek accountability.

“We didn’t get our answers yet. We got some of them, but it’s not over,” Mike McCauley said.

Sheila Brummer is IPR's Western Iowa Reporter, with expertise in reporting on immigrant and indigenous communities, agriculture, the environment and weather in order to help Iowans better understand their communities and the state. She's covered flooding in western Iowa, immigrants and refugees settling in Iowa, and scientific partnerships monitoring wildlife populations, among many more stories, for IPR, NPR and other media organizations. Brummer is a graduate of Buena Vista University.
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