When Dal­las night­club own­er Jack Ruby walked into the base­ment of the Dal­las Police Head­quar­ters and shot down Lee Har­vey Oswald — the accused killer of John F. Kennedy — he became the pudgy-faced prog­en­i­tor of an entire indus­try of con­spir­a­cy the­o­ries. In fact, as Dan­ny Fin­geroth points out in his new book, those two killings dur­ing the fate­ful month of Novem­ber 1963 sig­naled “ … the start, or at least accel­er­a­tion, of the age of con­spir­a­cy obses­sion.” There’s truth to this remark: the sus­pects accused of JFK’s mur­der range from the mob to Fidel Cas­tro, from the Rus­sians to Lyn­don John­son. And, forty years lat­er, most Amer­i­cans refuse to believe that either Oswald or Jack Ruby act­ed alone. 

To his cred­it, Fin­geroth avoids going down most of these well-plumbed rab­bit holes. Help­ful­ly (and a bit weari­ly), he even points out that the 1976 Select Com­mit­tee on Assas­si­na­tions, which was cre­at­ed to go back over evi­dence already inves­ti­gat­ed by the 1964 War­ren Com­mis­sion, was ulti­mate­ly unable to sub­stan­ti­ate the claim that more than one per­son was involved.

What real­ly inter­ests Fin­geroth is Ruby him­self. Born Jacob Ruben­stein in Chica­go, Ruby even­tu­al­ly relo­cat­ed to Dal­las. It was there — as a not par­tic­u­lar­ly suc­cess­ful night­club impre­sario, ​“a peren­ni­al small-timer look­ing for val­i­da­tion from every­one with whom he came into con­tact” — that he moved in a Run­y­onesque world of rounders, strip­pers, vice cops, and shtark­ers. Indeed, it was Ruby’s milieu that super­charged the­o­ries about him — the­o­ries hold­ing either that Ruby was a mob enforcer assigned to take out Oswald before he could squeal, or that the Dal­las PD knew what he was up to and delib­er­ate­ly let him get close to his vic­tim. Sure, Ruby prob­a­bly mixed with mob­sters. Who didn’t in his world? And he spent so much time ingra­ti­at­ing him­self with Dal­las cops, who could destroy a man like Ruby with a sin­gle liquor-license vio­la­tion, that they like­ly assumed that he was just anoth­er rub­ber­neck­er when he showed up at the Head­quar­ters that morning. 

It turns out that one of Jack Ruby’s moti­va­tors may have been his Judaism. A paid-up mem­ber of Shearith Israel — a ven­er­a­ble Con­ser­v­a­tive con­gre­ga­tion in Dal­las — Ruby was, if not an espe­cial­ly devout Jew, then one for whom com­mu­ni­ty was cen­tral. Like so many Amer­i­cans, Ruby loved JFK. But he par­tic­u­lar­ly admired him “ … for pros­per­ing despite prej­u­dice against Catholics, which he saw as not unlike the prej­u­dice Jews faced.” 

Although JFK’s ​“Ask not what your coun­try can do for you” inau­gur­al speech gave many Amer­i­cans a sense of hope­ful­ness, the John Birch Soci­ety and oth­er far-right extrem­ist groups were exert­ing real influ­ence on Civ­il Rights – era Amer­i­can pol­i­tics. In the days lead­ing up to the president’s vis­it to Dal­las, a city ​“where many vir­u­lent­ly hat­ed Kennedy,” Ruby was pro­found­ly dis­turbed by the mes­sag­ing that start­ed to pro­lif­er­ate. A mock ​“want­ed for trea­son” fly­er cir­cu­lat­ed, accus­ing Kennedy of improb­a­ble polit­i­cal and per­son­al crimes. A full-page ad in the Dal­las Morn­ing News char­ac­ter­ized the pres­i­dent as an incom­pe­tent Sovi­et dupe. Because the ad was signed ​“Bernard Weiss­man,” Ruby spec­u­lat­ed that it had been placed by ​“Jew hat­ing” provocateurs.

After his arrest, and dur­ing his sub­se­quent homi­cide tri­al, Ruby’s already quirky per­son­al­i­ty start­ed to trans­form into some­thing much dark­er. His pro­found sense of Jew­ish iden­ti­ty dete­ri­o­rat­ed into para­noid delu­sions. ​“There is going to be the great­est purge against the Jews of Amer­i­ca in all his­to­ry,” he told Rab­bi Hil­lel Sil­ver­man of Con­gre­ga­tion Shearith Israel, who stood by him through­out his tri­al. “ … it is a plot … you are next on the list.” 

Accord­ing to Rab­bi Sil­ver­man, Ruby’s sense of remorse stemmed not from killing Oswald, but rather from being a shan­da, for bring­ing shame upon the Jew­ish com­mu­ni­ty and unleash­ing (large­ly imag­ined) anti­se­mit­ic back­lash. While it broke him entire­ly, his defense lawyer, the great Melvin Bel­li, couldn’t quite get him off on an insan­i­ty plea. 

Ruby was nev­er able to explain why he killed Oswald — at least not in a coher­ent fash­ion. He may not be a lik­able char­ac­ter in this book, but there is some­thing com­pelling and strange­ly sym­pa­thet­ic about him. As Fin­geroth says, Ruby was in many ways ​“the clas­sic shli­mazel … a guy who could have been my weird cousin — or yours.”