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Police Dept. Finds the ‘Definitive’ Tool for Investigations

Updated: Apr 21, 2022


The Nampa Police Department (NPD) in Idaho, established in 1891, has about 134 full-time sworn officers. It serves approximately 107,000 Nampa residents and many others in the surrounding area.

The department has been led by Chief Joe Huff since November 2015. NPD's mission statement is: "Through integrity, teamwork and excellence, it is our mission to respectfully protect and serve our community."

Detective Mark Palfreyman, currently working in the NPD property crimes unit, is in charge of the EyeDetect program. He is a certified polygraph examiner and has conducted polygraph exams for over 12 years. He has 16 years of combined experience conducting investigations for NPD with previous experience in person crimes for about 13 years. Detective Palfreyman uses EyeDetect primarily in criminal cases and most often in sexual abuse cases involving juvenile victims.


Detective Palfreyman is not only dedicated to uncovering and helping hold guilty parties accountable, but he also enjoys helping to exonerate innocent persons. “I try to help innocent people get out from under the umbrella of suspicion,” he says. A recent lateral transfer job candidate took a pre-employment polygraph exam administered by another NPD examiner, who then asked Detective Palfreyman if the same candidate could be tested with EyeDetect. Palfreyman agreed and the results of the polygraph and EyeDetect tests concurred. After the testing, the candidate provided additional information about previous unreported work-related discipline at the candidate’s prior police agency.


Detective Palfreyman began using EyeDetect in criminal investigations in January 2020. Because it is new and less known, he prefers to administer an EyeDetect number test first to introduce suspects to the technology and to determine if the person will be compliant. In a number test, the participant picks a number between 2 and 9 and responds to a series of true/false questions in which the participant denies choosing a number. EyeDetect correctly identifies the number chosen about 90% of the time. According to Palfreyman, truthful people want to make sure EyeDetect works, to clear themselves. Guilty persons, on the other hand, hope the test isn’t accurate. Detective Palfreyman noticed that when a guilty person sees the number test work, they get nervous and think, "Oh no…it's going to catch me!" Whereas a truthful person is excited to take the EyeDetect criminal test and they typically pass with a strong credible (truthful) result. Palfreyman says, “If I could only use one credibility assessment tool in a criminal investigation, it would be EyeDetect. I do have a high degree of confidence in polygraph as well. However, I love the fact that EyeDetect is faster and is free of any examiner influence or bias. The process is simple and clean — the person receives basic test instruction and information from the examiner, and then answers questions on a computer. That information is uploaded and scored by a computer algorithm. Science and research indicate EyeDetect is accurate, effective and lives up to its tagline: ‘the eyes don’t lie’.”

Detective Palfreyman says EyeDetect has been his primary tool of choice for credibility assessment testing in criminal investigations. He also indicates it’s exciting when EyeDetect and polygraph tests are run independently by different examiners and both test results concur.

As science and research indicate, the confidence rate goes through the roof when that happens, declares Palfreyman. “EyeDetect really works,” said Palfreyman. “We've had great success.

Investigators at NPD have asked me to use EyeDetect on many of their cases.” One notable case in February 2020 involved theft at a home fire. No evidence of arson was found. But after firefighters cleared the home, the homeowner claimed a large sum of money had been stolen from a bedroom. The homeowner was asked to take an EyeDetect test. “Absolutely. I wouldn't say this if it wasn't true,” she said. And she easily passed the test.

Three others had access to the home and knew of the money: (1) a daughter (who lived there), (2) a granddaughter, and (3) the homeowner's boyfriend. All were tested, and the daughter failed. The daughter, who had a history of drug use, claimed, "No, no, no. I'm being truthful!" During a post-test interview with police (and with her mother present for part of it), the daughter essentially said, "Mom, you know I didn't take your money, right?" The mother basically responded, "Yeah, I know. Let's go." They then left NPD together. It appeared this woman (homeowner/victim of theft) “enabled her daughter a lot of her life," said Detective Palfreyman. "EyeDetect was very effective. It ruled out people and we strongly believed it correctly identified the suspect. We didn't get a confession and the case was inactivated due to lack of evidence. But we were zeroed in.”

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