From Halopedia, the Halo wiki
B.M. Parkes is an Office of Naval Intelligence behavioral analyst. On May 8, 2551 Parkes gave a Hemley & Aubourn Behavior Analysis to Catherine Halsey. Parkes noted that Halsey was "not terribly forthcoming." Although noting that Halsey's exceedingly high cognitive performance score may distort the rest of the results, Parkes was confident that the analysis was mostly accurate. Due to Halsey's atypically high "Liability" index, Parkes' report recommended that ONI assign 2-3 handlers to keep track on the doctor at all times and strongly advised against allowing her to leave Reach.