State Supreme Court considers role of lie detectors in sentencing

Inmate’s request for new hearing sparks broader debate over admissibility

By: - March 23, 2023 6:09 pm
South Dakota Supreme Court Justice Janine Kern gestures as she participates in oral arguments with other justices on March 23, 2023, in Brookings. (David Bordewyk/South Dakota Newspaper Association)

South Dakota Supreme Court Justice Janine Kern gestures as she participates in oral arguments with other justices on March 23, 2023, in Brookings. (David Bordewyk/South Dakota Newspaper Association)

BROOKINGS — A man who contends he was not the shooter in a 2020 robbery-turned-homicide in Sioux Falls wants the South Dakota Supreme Court to order a judge to consider the results of his polygraph test at a new sentence hearing.

Ray Banks is serving an 80-year sentence for manslaughter for his role in the shooting death of a pizza delivery driver. His co-defendant, Jahennessy Bryant, cut a plea deal to cap his prison time at 25 years. 

Bryant told police that Banks hatched the robbery plan and fired the two shots that killed 30-year-old Casey Bonhorst on Feb. 26, 2020. 

Prior to the plea deal, only Bryant had been charged with manslaughter. The plea deal put both men’s names on the indictment for Bonhorst’s death.

Polygraph admissibility

During law enforcement interviews, Banks had maintained that Bryant was the shooter, and Banks took a polygraph test — sometimes referred to as a “lie detector test” — to bolster his case at sentencing. Banks also took a plea deal, and had hoped to use the polygraph results to push for a lighter sentence than the 80 years, with 20 suspended, outlined in that agreement.

The judge balked at the polygraph request. 

Polygraph results are not admissible at a criminal trial in South Dakota, as there are questions about reliability. For that reason, Judge Robin Houwman denied Banks’ request to have the polygraph examiner testify at the December 2021 sentencing hearing for both defendants.

In Banks’ appeal to the South Dakota Supreme Court, his lawyers argue that Houwman’s decision was a mistake. The rules of evidence that bar the consideration of things like polygraph results, hearsay evidence, or evidence of previous criminal behavior by a jury typically do not apply at a sentencing hearing. 

Victims or the families of victims are allowed to offer victim impact statements without fear of objection or cross-examination from defense attorneys, for example, and defendants are offered similar latitude to explain the circumstances in their lives that led them down the path to criminal behavior. 

Banks contends in his appeal that the application of a rules-of-evidence standard at a sentencing hearing presented a barrier to justice. His polygraph results showed no sign of an intent to deceive as he talked about Bryant’s role in the shooting. 

That should’ve been considered at sentencing, Banks’ lawyers said during Thursday’s oral arguments before the high court.

Justices pose questions

Justices had pointed questions about his request. Several justices pointed out that Banks was allowed to make the argument that he wasn’t the shooter and talk about the polygraph results. They also pointed out that while the rules of evidence do not apply at sentencing hearings, judges are not bound to admit every piece of potential evidence a lawyer might want to use.

Refusal to consider polygraph test information may be a matter of discretion and a recognition that the tests are considered too unreliable to bother with, Justice Scott Myren said. 

Justice Janine Kern questioned whether there’s evidence that the tests have improved.

“Has this technology advanced to such a degree that they are now generally accepted by the scientific community?” Kern said.

Appeals courts, Kern noted, often rule against the use of polygraph tests at sentencing hearings.

Attorney Kristi Jones, representing Banks, said the technology remains under suspicion. Even so, she argued, a judge ought to be obliged to consider them on a case-by-case basis after hearing from the person who conducted the test — not before.

“We were prohibited from submitting testimony from the person who took the lie detector test, and the lie detector test itself,” Jones said.

Preliminary breath tests (PBT) collected in drunken driving cases are similarly frowned upon by the scientific community, Jones said, but are discussed at sentencing by prosecutors. The high court ruled in favor of prosecutors on the admission of PBTs at sentencing in a case titled State vs. Huettl.

Justice Mark Salter pressed Jones on the implications of a ruling in Banks’ favor. What if the state, in a case involving drug possession, were to submit a police detective’s report based on a person who heard from someone, who heard from someone else, that the defendant had dealt drugs at some point in the past?

Such a report might lead a judge to conclude that a defendant who’d otherwise get a probation sentence deserves jail or prison time, Salter said. 

Would that be acceptable, he asked?

“I understand that it opens the door to a vast amount of information coming in at a sentencing hearing,” Jones said. “I will submit to the court that that’s why we trust judges to weigh that evidence appropriately.”

State responds

Assistant Attorney General Paul Swedlund, arguing on behalf of the state in the Banks case, told justices that judges aren’t obligated to say yes to every request for testimony at sentencing simply because they can. 

“Evidence at sentencing must be relevant and it must be probative,” Swedlund said. “Polygraph evidence is neither.”

When asked by Justice Kern if the polygraph could’ve made a difference for Banks, whose sentence was significantly longer than his co-defendant’s, Swedlund said that the judge had far more to go on than Bryant’s testimony alone.

Banks told his girlfriend that he was the shooter, Swedlund said, and there was a host of other information reported throughout the course of the investigation that suggested he was more than a lookout.

Swedlund told the justices that inmates who’ve killed someone sometimes get a teardrop tattoo to show they’d done so. At one point, Swedlund said, “Banks bragged about instead getting a tattoo of a pizza slice that would signify he had killed Bonhorst,” who was a pizza delivery driver.




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John Hult
John Hult

John is the senior reporter for South Dakota Searchlight. He has more than 15 years experience covering criminal justice, the environment and public affairs in South Dakota, including more than a decade at the Sioux falls Argus Leader.