From Outlaws of the Marsh, translated by Sidney Shapiro

The second [bandit] was Jiang Jing, from Tanzhou in Hunan. Originally he had studied for the imperial examinations. But when he failed to pass, he abandoned the pen and took up the sword. A clever fellow, he was a skilled mathematician. In ten thousand calculations, he was never off an iota. He was also good with a lance and staff, and a skilled tactician in battle. And so he was known as the Magic Calculator.

This inspired me to google Kenneth Krohn, the co-developer of the Krohn-Rhodes theorem which discovers an unanticipated group structure in finite state machines. I’d heard rumors that Krohn had troubles and find

The petitioner testified before the board that a Mexican national (victim) had swindled him out of a large sum of money in the early 1970’s, at a time when the petitioner was living in Mexico under the alias Henry Blackwell. The petitioner was charged with kidnapping but pleaded guilty to the lesser offenses. At his plea hearing, he admitted that he and another individual used a false identity to lure the victim to Dulles International Airport for purposes of extorting the money.(4) The petitioner admitted that his coconspirator met the victim at the airport and took him to a car “rented by [the petitioner], using [a] . . . credit card” under another false name. The victim was taken to an apartment in Maryland that had been rented and “coerced to write approximately seven letters to member of [the victim’s] family.” The letters were in the victim’s handwriting and had the petitioner’s fingerprints on them. The letters instructed various persons to dismiss a lawsuit the victim had instituted against the petitioner, and to transfer assets to the petitioner (i.e., Henry Blackwell). As part of the plea, the government agreed not to prosecute the petitioner for any other crimes related to the case and the petitioner expected to serve approximately three and one-half years in prison. The petitioner was sentenced to ten years’ imprisonment and he served approximately three years of his sentence.(5)

These felonies are very serious and were, one may fairly conclude, committed as retribution for a wrong perpetrated on the petitioner by the victim. At the time the petitioner committed the crimes, in 1973, he was thirty-five years old, and held a master’s degree and a doctorate from Harvard University, which he earned in the 1960’s. His doctorate is in mathematics. He was accomplished in his field. He coauthored a computer science theory that was published in a textbook. He had owned, and sold at a profit, his own computer business making him financially secure. He also owned property in Washington, D.C. See Matter of Prager, 422 Mass. 86, 96 (1996) (admission to bar denied despite board recommendation for admission; at time applicant committed felonies, he was mature, well educated, and possessed adequate financial resources).

When mathematicians get mad