The Idaho Four Stairwell Stains: What the DNA and Bloodstain Reports Actually Establish

The Idaho Four Stairwell Stains: What the DNA and Bloodstain Reports Actually Establish

Published October 28, 2026 | Under the Magnifying Glass | Forensic document analysis. This is an analysis of records disclosed in the criminal case, not an account of new laboratory testing or a new court ruling. No graphic crime-scene or autopsy photographs are reproduced.

The Case, Simply Explained

On November 13, 2022, four University of Idaho students, Kaylee Goncalves, Madison Mogen, Xana Kernodle and Ethan Chapin, were murdered at 1122 King Road in Moscow. Years later, the filed reports of two bloodstain specialists gave the public a way to understand a detail in the house: three labeled stains, 23, 24 and 27, near the stairs leading from the second floor to the first. The photograph is easy to turn into a mystery. The laboratory record requires more care.

Prosecution expert T. Paulette Sutton described all three as presumptively positive in blood screening, with a distribution consistent with blood released from an object in motion and with appearances consistent with dilution. For a sample associated with stain 27, the reported DNA mixture contained a major component matching Kaylee Goncalves and a possible minor component attributable to Madison Mogen. Sutton also wrote that the physical evidence did not place either woman in that stairwell after she was wounded. A stain can show material reached a surface without showing that the person whose DNA it contains stood there.

Why It Matters

This distinction is central to responsible reporting. A photograph can show a location. A presumptive test can indicate that a substance may be blood. DNA analysis can associate biological material with someone. Bloodstain-pattern interpretation can offer a possible mechanism. None of those steps, standing alone, identifies every movement, explains exactly which object was involved, or reconstructs every second of the crime.

A second issue makes the document trail especially important: defense expert Matthew Noedel identified a numbering mismatch between scene markers and sample identifiers used in later laboratory records. Sutton investigated it, agreed corrections were warranted and withdrew one earlier conclusion concerning another stain. Readers should see those corrections, not treat every number printed in an early report as an unchanging fact.

Go Deeper: The Location and the Labels

Where exactly were stains 23, 24 and 27?

Sutton’s revised report, at paragraph 36 on its printed page 35 (PDF page 61, counting the cover and preceding exhibits), identifies the location as the stairwell from the second level toward the first. It places stains 23 and 24 on the north wall and stain 27 above the steps. The overall photograph is identified as DSC_4430; closer images are DSC_4400, DSC_4402 and DSC_4435. Those are photographic references, not independent laboratory case numbers.

The distinction matters because discussions online sometimes treat the number on a visible marker, an item number used by a detective and the laboratory’s accession number as interchangeable. The revised filings show that they were not always interchangeable. This article uses the scene-placard labels when discussing the visible stairwell stains and specifies when a separate laboratory result is being described.

What the testing showed, and what it did not

First, screening. Sutton cited the Idaho State Police Forensic Services field report for presumptive positive tests at all three locations. Presumptive means the test is designed to flag possible blood; it is not the same as a complete identification of human blood from a particular person. A reader should not describe every photographed stain as individually DNA-matched merely because one nearby stain yielded a reported profile.

Second, pattern. Sutton characterized the locations and distribution as consistent with cast-off, meaning drops released from a blood-bearing object in motion. She also assessed the appearance as consistent with diluted blood, in which blood has mixed with another liquid. These are expert interpretations of physical features. The report does not identify the specific object, identify the other liquid, or supply a video-like sequence of movement.

Third, DNA. The report identifies a mixture associated with stain 27 in which Kaylee Goncalves matched the major component and Madison Mogen was a potential minor contributor. That is different from saying that both individuals independently bled at the stairwell, and different again from saying both people traveled down those stairs after their injuries. The source report explicitly warns against the latter inference.

A nearby area is relevant, but not identical

The revised report discusses another set of stains close to the second-floor living-room half wall and the beer-pong table. Sutton described stain 26 as diluted cast-off with associated flow, also reporting a DNA mixture with Kaylee as major and Madison as potential minor contributor. She interpreted stain E on the wooden ledge as diluted spatter moving toward the opening to the stairs, but said stain E received no further testing. Connecting those neighboring observations is a legitimate reconstruction question; conflating their placard labels or claiming identical test results is not.

The critical correction: three numbering systems

Noedel’s January 22, 2025 reconstruction criticized the way sample and placard numbers had been matched. He explained that the original scene markers catalogued by Detective Talbott included numbers 23 through 49. When swabs passed into Detective Payne’s evidence sequence, corresponding items ran 17 through 43. In that sequence, scene placard 23 would correspond to Payne item 17, a difference of six. Laboratory reports could then carry further laboratory reference numbers. Without the crosswalk, a later reader could incorrectly attribute a DNA result to the stain shown beside a different marker in a photograph.

Sutton’s February 13, 2025 revised report acknowledges the issue. After obtaining the original Moscow Police evidence log and reviewing laboratory worksheets, she amended results associated with multiple locations, including markers on the upstairs bedroom door, a third-to-second-floor handrail, and locations near Xana Kernodle’s bedroom. She deleted an original conclusion about stain F at the beer-pong table because its DNA association had been erroneous. The revision is not evidence that none of the laboratory testing can be trusted. It is evidence that the mapping of particular sample identities required correction and that older conclusions must not be quoted without checking the revised version.

An additional caution from the rebuttal is revealing: Sutton accepted that Noedel had seen one stain at the scene before later testing, while Sutton’s description had relied on an image after sampling. Both recognized that collecting a sample can change a stain’s appearance. That means a photograph taken after swabbing may not preserve all the features a pattern analyst would ideally want for an original-scene interpretation.

Where the experts agree, and where questions remain

Both the filed defense reconstruction and Sutton’s response emphasize the importance of original photographs, a reliable link between a visible scene location and its sample, and caution when interpreting altered stains. They did not agree on every inference from bloodstain patterns. Sutton’s final conclusions said that someone other than the victims carried or possessed the source of blood responsible for stains outside the bedrooms, and that the cast-off near the second-to-first-floor stairwell indicated motion. She separately said the evidence did not exclude a single perpetrator. These are her documented opinions, not findings reached after a contested expert trial.

What remains unknown from the pictured markers alone is the exact object responsible, the precise moment each mark was deposited, the identity of any liquid that diluted blood, and whether a particular person’s body was physically present at the stairwell. An online explanation that confidently answers all four questions without showing more primary evidence goes beyond what these markers prove.

What about a video asking readers to ‘explain this’?

A new video thumbnail circulating under the title The Bloodstain Files, Episode 1 highlights these same numbers. The screenshot establishes the creator’s topic, not the accuracy of every spoken claim. Until the full episode and its cited records can be independently checked, it should be labeled media commentary and a lead for source review, not a new forensic discovery. The stronger answer begins with the filed exhibits and lab notes.

Why the jury never resolved this dispute

The expert material was prepared in litigation over a planned trial, but Bryan Kohberger pleaded guilty in July 2025. He was sentenced on July 23, 2025 to four consecutive fixed life terms without parole for the murders and a fixed ten-year term for burglary. The plea resolved the criminal charges without a murder trial jury hearing and weighing these experts’ competing theories. A contested forensic interpretation is not automatically a finding that another person committed the crimes, nor is the absence of jury testimony proof the reports were unimportant.

What Happens Next

The productive next step is document-by-document comparison: the earliest in-situ images, swab collection logs, Payne’s item sequence, ISP laboratory worksheets, the original Sutton report, Sutton’s February 2025 revision and Noedel’s reconstruction. Any future documentary or creator coverage should be checked against those precise pages, rather than against the caption on a thumbnail. The question is not whether a stain is intriguing, but what each record actually supports.

Our continuing Idaho Four Evidence Index and scene-reconstruction guide provide related context. Preserve the difference between original forensic observations, later corrections, expert opinions, and findings from court proceedings.