In the latter part of 1933, there was an epidemic of truck hijackings in the states of Virginia, Maryland, and Pennsylvania; this was the work of 6 gangsters: the Tri-State Gang. Tonight, in Richmond, Virginia, they're hijacking a truckload of radios. As usual "Big" Bill Phillips, a 6'4" ox of a man, takes over the hijacked truck, transferring the load onto their truck; Artie McLeod, a cheap tin-horn gambler, puts a burlap sack over the driver's head, blinding him, and chains the driver to a tree. Other gang members are Georgie Kaufman, an ex-boxer, the oldest of the gang; and James Jonathan Harris, aka Gentleman Jim, aka "Harris the Fence"; and the 2nd-in-command, Bobby Mais. Their leader is the vicious, sadistic Wally Legenza-- he shoots 4 bullets into the driver (who never got a good look at the gang members, and couldn't identify them) because Legenza is a psychopath. Ness and his men, who had been assigned by Washington, DC, to investigate the Tri-State Gang, are on the scene.
May 14, 1934. That night, Wally Legenza calls a meet, to go over tomorrow night's hijacking job. "Big" Bill Phillips is absent-- he's seeing his sweetie, Elizabeth "Lizzie" Dauphine, a French girl from Quebec, Canada that he nicknames Alouette. Legenza goes to their place and breaks it up. The night of May 15, in Oakhurst, Virginia, the gang hijacks a truck hauling $20,000 of tobacco. Again they chain the driver to a tree, but this time Legenza only shoots one bullet into him; the driver doesn't die, and when the sack over his head falls off, he sees their license plate number: T-4514.
Ness and his men are staying in Richmond; Ness investigates this first break in the case. The Dept. of Motor Vehicles shows the truck is registered to Briggs Salvage Co.; the Internal Revenue shows the owner is James J. Harris. Ness and his men stake out the Briggs Salvage place; it is virtually deserted, only Harris and one watchman. But on the 5th night, Harris shows up with Legenza and "Big" Bill Phillips. There's a shootout. Phillips shoots LaMarr Kane; Ness shoots Phillips. Harris and Legenza escape. LaMarr Kane dies. Bill Phillips dies, too-- his last word is mumbling "Alouette," which Ness only hears as "Al"-somebody.
To make sure they can't be identified, Legenza tells Georgie Kaufman to knock off that "French pastry" that Bill Phillips had been seeing. Georgie goes to her place, and shoots her once; but she survives and winds up in the hospital. Ness is contacted and informed that Lizzie Dauphine was Phillips' girlfriend. Next, Legenza sends James J. Harris to bump her off; but Ness and his men are guarding the hospital, inside and out. As James Harris tries to sneak into the hospital by going up the fire escape, Ness spots him; James Harris fires his gun, and Ness shoots him-- Ness recognizes him as "Harris the Fence." Ness then gets Lizzie Dauphine to name names. Later, bungling Georgie Kaufman is found in his car, riddled with machine gun bullets. (there are now only 3 gang members left alive.)
Legenza figures they need $60,000 to skip the country. They can get it by kidnapping, and they put the snatch on Willie Weinberg, a bookie. Artie McLeod takes them all to a new place, being rented by a blonde he knows. Legenza phones Willie's wife, Flora, and demands the money; but next morning, she's only raised $28,000. Legenza gives her another day, to call Willie's brother in Baltimore for the rest of the money. That night, Legenza figures they can get the other $32,000 without Willie, so he and Bobby Mais take him for a "one way ride." Legenza shoots Willie, but they can't dump the body in the river like they planned, because of a police roadblock. They dump the body by the road, where they think it won't be found for days, but it's discovered an hour later.
Ness tells Flo and Sidney that Willie is dead; they offer to cooperate to capture the kidnappers, they'll drop the money off as planned: in the zoo area of McDowell Park. Next morning, Ness and his men and some police are watching; Ness is dressed in a groundskeeper uniform. When the gangsters go to retrieve the money, there's a shootout. (with park visitors running for cover!) Flaherty and Rico shoot Bobby Mais. Artie McLeod, surrounded by 3 cops, wisely surrenders. Legenza tries to escape, and stupidly goes over the fence into the polar bears exhibit; he falls down a ledge and breaks his legs. And that's how Legenza's Tri-State Gang ended, not with a bang but a whimper, with him pleading, "Help-- help me," over and over. Artie McLeod was convicted on seven counts and got life in prison. Legenza died in the electric chair on February 2, 1935. Little Lizzie Dauphine made it home to Quebec.