Bill Chalker is an Australian scientist and researcher of unidentified anomalous phenomena (UAP), trained in mathematics and chemistry, who became the first civilian researcher to gain access to the Royal Australian Air Force’s UAP files in the early 1980s.1 He is best known for his long-running investigation of the alleged alien encounters of Peter Khoury, including forensic DNA analysis of a hair sample said to have been recovered from one of the encounters, published in his book Hair of the Alien: DNA and Other Forensic Evidence for Alien Abductions (2005).
Chalker began researching Khoury’s case in 1993, the same year he learned of the 1993 Kelly Cahill case.2 He first heard of Khoury’s 1992 encounter many months after it had occurred,3 and Khoury initially chose not to share details of the experience with him,4 only revealing the full story of the 1992-07-23 Peter Khoury bedroom encounter in 1996.5 Given the significance of the hair evidence, Chalker set out to establish with some certainty that the sample had been obtained the way Khoury described.6 By early 1998 his network of scientific contacts, an informal “invisible college” of researchers who took the UFO phenomenon seriously,13 had expanded to include biochemists, who worked under strict anonymity given the subject’s standing as “forbidden science”.78 This group called itself the Anomaly Physical Evidence Group (APEG), with Chalker acting as its public face.9 The invisible college of UFO researchers discussed using polymerase chain reaction (PCR) amplification and sequencing of mitochondrial DNA on the hair sample.10
Two distinct phases of Deoxyribonucleic Acid (DNA) profiling analysis were carried out on the hair,11 which Chalker states is the only anomalous sample from the case and yielded a strange DNA profile.12 The original analysis confirmed the hair came from someone genetically close to normal humans but of a very unusual racial type.14 Chalker concluded there was no coherent evidence that Khoury had fabricated his account of encountering two women and recovering the hair sample in July 1992.15 The Deoxyribonucleic Acid (DNA) profiling technique used addresses the credibility of claims that alien abductors pursue a genetic agenda.34 Chalker separately DNA-tested a hair sample connected to Mike Wood (mid-north coast New South Wales businessman); it did not display the same anomalies as Khoury’s sample.35 A preliminary mitochondrial DNA PCR comparison found both that sample and one taken from Mike Wood’s daughter to be within the normal human consensus range, though different from one another.36
Chalker’s investigation extended to reconciling apparent inconsistencies in Khoury’s testimony. He wrote to Moira McGhee and Bryan Dickeson requesting a copy of their 1992 McGhee/Dickeson taped interview with Peter Khoury,17 which took several years for McGhee to locate and pass to him.18 Comparing the tape against Khoury’s later hypnotic recollections, Chalker concluded the evidence pointed to two separate encounters with the same two women rather than one, one in October 1991 and one in July 1992.19 Khoury’s hypnotic account of the 1992-07-23 Peter Khoury bedroom encounter was found to be largely consistent with his conscious recollections.20 Chalker played the full taped interview to Peter and Vivian Khoury together to see whether it would trigger further recollection or clarify the 1991-10 Peter Khoury bedroom encounter.21
Chalker’s engagement with the Peter Khoury alien abduction case followed his contact with Kelly Cahill, who first approached him on 1993-10-04 about her encounter.16 He was unable to gain full access to Phenomena Research Australia’s data on the Cahill case and came to regret involving that organisation in the investigation,23 a frustration that Chalker said made him more determined to extract the full potential of the physical evidence in the Khoury case.24 Chalker considered the Cahill case one of the few compelling exceptions to the ambiguity he otherwise found pervading the alien abduction phenomenon,28 saying he generally found physical traces in UFO landing events particularly compelling evidence for the physical reality of UFOs,29 and that most abduction cases he encountered conspicuously lacked compelling physical evidence.30 He has said he works alone on UFO research and works for “the Invisible College”.33
Beyond the Khoury and Cahill cases, Chalker interviewed former student Victor Zakry, who claimed to have seen the Westall object at ground level.37 He also befriended fellow Australian UAP researcher Harry Turner late in Turner’s life.38 Whitley Strieber asked Chalker to investigate a 1976 New South Wales encounter after receiving a letter describing it.25 Chalker interviewed Peter Khoury’s family, including his brother Sam Khoury and their father, while researching his book on the case, recording audio and taking notes but no video.3132 He was also present when Khoury confronted the Skeptics Association (Australia) at the Powerhouse Museum in Sydney.27