He was a burly, broad-shouldered man, and a focused, intense, and determined officer. By 1920 PD, he held the rank of Captain and served in the Office of Naval Intelligence's Criminal Investigation Division.
Mandel was charged with investigating the attempted murder of Admiral Honor Harrington, but did not believe in Harrington's claims to have felt Timothy Meares' true emotions through her link to her treecat, Nimitz. When she realized that he would not investigate in that direction, Harrington relieved him of his authority over the investigation, and replaced him with his deputy, Commander Jean Simon. (HH11)