This story begins in late March 1965, when Jack Franck, an auto mechanic from New York City, purchased two Lahti 20 mm anti-tank rifles and 200 rounds of armor-piercing ammunition at the Alexandria, Va., offices of Interarmco.
He paid approximately $800 for the two massive firearms (each Lahti L-39 AT rifle weighs in at 109 pounds and is more than seven feet long).

The Lahti is a massive rifle at more than seven feet long and weighing nearly 110 pounds. Image courtesy of SA-Kuva.
Franck requested that the rifles be delivered to a Plattsburgh, N.Y., address. Plattsburgh is a small community in northern New York state, about 70 miles due south of Montreal. Interarmco employees were suspicious, and Franck’s story didn’t seem quite right, so they contacted the FBI.
After some cursory investigation, the FBI believed that Franck was attempting to smuggle the guns into Canada to help equip the “Federation du Liberation du Quebec” (FLQ), the Quebec Liberation Front.
The FLQ was a militant Marxist revolutionary group intent on establishing Quebec as an independent state by any means necessary.
The terrorist organization began operations in the early 1960s, and by the time they were eliminated in 1970, the FLQ had killed eight people and wounded several others (many during their infamous bombing of the Montreal Stock Exchange in February 1969). The FBI notified Canadian authorities about their concerns.
Waiting for the Lahti AT rifles to arrive in Plattsburgh was Joel Singer. Singer, 22, was a native of Montreal, and young man with a criminal record in Canada. Jack Franck was his uncle.
The big rifles in their crates arrived in Plattsburgh on April 5, 1965, and were held in a storage facility, awaiting pick-up. Singer apparently suspected that the firearms were being watched by the police, and made no move to claim them.
Instead, Singer waited until the weekend, and under the cover of darkness on a Sunday night, broke into the warehouse and removed the rifles his uncle had purchased. The break-in was discovered on Monday morning as employees reported to work.
Six months passed. On Oct. 23, 1965, Singer and up to five accomplices traveled from Montreal to Syracuse, N.Y. Singer’s gang had targeted the Brinks armored car facility located at near the intersection of Lodi Street and Lemoyne Avenue.
On the night of Oct. 24, Singer’s gang carried out their break-in. It was suspected that Singer’s men had a strong understanding of the layout of the building, and they carefully skirted the Brinks’ alarm systems.

The Lahti anti-tank rifle linked to the Syracuse robbery. The FBI pulled it from the waters just off the shore of Garden City, Long Island.
They managed to open the garage door and then were able to drive their DeSoto wagon, carrying the Lahti AT rifle and the rest of their burglary tools, directly into the building. The gang had modified the Lahti for their purposes.
They created a large canister-like suppressor and attached it the end of the barrel. They also used several mattresses and heavy blankets to help muffle the blast of the 20 mm cannon. Singer’s men had also developed a special mount for the AT rifle to help them blast through the foot-thick cement and steel reinforced vault wall.
Singer’s gang fired up to 33 armor-piercing rounds in a circular pattern through the vault wall, creating an approximately 18” x 24” passageway. A tight fit, but large enough for a small gang member to crawl through.
Evidence collected by police showed that the burglars brought along nitroglycerin, gas masks, welding equipment, and other heavy duty tools to force their way into the vault. The penetrating power of the Lahti did the trick and the spent 20 mm shell casings were left on the floor.
Singer’s gang gathered up almost $425,000 in cash, coins and checks, and drove away from the crime scene, amazingly unseen and unheard.
They left behind several tools though, including a number marked “Made in Canada.” Initially, police developed a multi-state search for the gang, but Canada soon became the primary search area when it was learned that an unsuccessful burglary attempt was made in Quebec earlier in the year, and a Lahti 20 mm AT rifle was found at the scene.
Within a day or two of the crime, Joel Singer visited his uncle Jack Franck in the New York City area. Franck would later testify that Singer gave him $200 for his help in acquiring the firearms, and described that he was behind the Syracuse robbery.
Shortly after Singer left, Franck contacted the FBI and asked for immunity in exchange for his testimony. Franck became the key witness for the prosecution, and described how he and Singer had dumped the Lahti anti-tank rifle into the ocean near Jones Beach on Long Island.
The gun was quickly recovered, and ballistic tests linked the weapon to the shell cases left behind at the scene of the Brinks robbery in Syracuse.
The FBI put Singer on their “Ten Most Wanted” list on Nov. 19, and by early December Singer was apprehended in Montreal, and was later extradited to Syracuse to stand trial.
On Jan. 31, 1967, after a two-month trial in Onondaga County in which his attorney attempted to portray him as a “lovable idiot,” Singer was convicted of third-degree burglary and first-degree grand larceny.
He was sentenced to serve five to 10 years in the maximum security Attica State Prison. Throughout his trial, Singer remained silent as to the identity of his accomplices.
He was the only person convicted in connection with this robbery, and only $166 worth of coins (found at Franck’s residence) was ever recovered from the stolen cash.

The Lahti AT rifle from the Syracuse robbery displayed outside the courtroom of the Onondaga County Courthouse in January 1967.
Singer was serving time in Attica when the massive prison riot broke out during September 1971. This violent incident apparently scarred Singer deeply.
He was transferred to a psychiatric facility in July 1972, and was released from custody in October. Singer returned to Montreal, but could not escape his demons. On Feb. 6, 1973 he committed suicide by taking cyanide, closing the book on a strange-but-true crime, and a bizarre application of a rare firearm.

Thunderbolt & Lightfoot
There is a significant plot point similarity between this United Artists film and the Brinks robbery in Syracuse. “Thunderbolt & Lightfoot” starred Clint Eastwood, Jeff Bridges, George Kennedy and Geoffrey Lewis, and was released in May 1974.
The film was written and directed by Michael Cimino. The main character is a bank robber called “The Thunderbolt” (played by Eastwood), known for his use of a 20 millimeter cannon to blast his way into a bank vault.
Thunderbolt is described as a Korean War veteran, credited with destroying several Communist tanks using a 20 mm anti-tank gun. That’s an unfortunate error, as the 20 mm Oerlikon gun used by Lightfoot in the film was never issued to American forces as an anti-tank gun.
Regardless, the use of the 20 mm cannon in the movie is quite similar to Singer’s concept to blast his way into the Brinks vault.
Overall the movie is well done and an enjoyable action film. The unique (and plausible) firearms tie-in is simply armor-piercing icing on the cake.
The 20 mm Lahti L-39 Anti-Tank Rifle
The L-39 was created by Finland’s famous arms designer Aimo Lahti, just in time for a handful of the new AT rifles to see service during the Soviet invasion of Finland (the “Winter War”) of November 1939-March 1940.
The semi-automatic, gas-operated Lahti AT rifle proved quite effective against the Soviet tanks deployed during the Winter War, its 20mm AP shot traveling at 2,600 FPS. When Finland committed to the “Continuation War” against the Soviet Union in the late June 1941, Soviet tanks had grown in size, armament and armored protection.
The effectiveness of the Lahti AT rifle became limited to sniping at hatches and optics, along with shots at the thinner armor on the lower side of the chassis and rear of the Soviet tanks.
The Finns continued to put the big 20mm rifle to use by using it in the counter-sniper role, often baiting Soviet marksmen into shooting at strawman targets to reveal their position, and then subjecting them to 20 mm AP shot in return fire.
The powerful 20 mm rounds were particularly effective at penetrating cover, and were often used against machine gun bunkers and hardened artillery positions.

Studio shot of the Finnish 20mm L-39 AT rifle, showing details of the combination sled-and-clawfoot bipod. Image courtesy of SA-Kuva.

The L-39 is semi-automatic, and gas operated. The 20 mm rounds feed from a 10-round magazine. Image courtesy of SA-Kuva.

The L-39 packed in its transit case. This was essentially how the firearm was sold in the USA beginning in the mid-1950s. Image courtesy of SA-Kuva.
Beginning in the mid-1950s, the Lahti AT rifles began to be advertised by American surplus arms dealers. For several years the Lahti L-39 was priced at $99 in its transit case and with a full complement of accessories.
The Lahti was originally available without restriction*, but since it is larger than .50 caliber (12.7 mm), it was labeled a “destructive device” and subject to NFA regulations by the Omnibus Crime Control and Safe Streets Act of 1968, and the Gun Control Act of 1968.
(*I was born about 30 years too late! Grumpy)