They Sent 40 ‘Criminals’ to Fight 30,000 Japanese — What Happened Next Created Navy SEALs

At 8:44 a.m. on June 15, 1944, the water surrounding Saipan’s southern reefs churned with the violence of a man-made storm. First Lieutenant Frank Tachovsky crouched low in the steel belly of a Higgins boat, three hundred yards from shore, listening to the terrifying percussion of Japanese artillery walking across the surf. The twenty-nine-year-old officer from New Brighton, Pennsylvania, was not leading a standard Marine platoon. The forty men breathing heavy, humid air behind him were not the poster boys of recruitment drives. They were the “40 Thieves,” a unit forged from the dregs of the brig and the violent castoffs of the Second Marine Division.

Their mission was suicide by any conventional military standard: to operate alone behind enemy lines for days, mapping a garrison of 30,000 Japanese troops who were dug into the volcanic rock like ticks. Marine Corps planners had coldly calculated that units like Tachovsky’s—scout snipers—averaged a 73% casualty rate in the Pacific. But Tachovsky wasn’t banking on averages. He was banking on the specific, brutal criteria he had used to select his men.

The Genesis of the Thieves

Seven months prior, the Marine Corps had bled out on the coral of Tarawa, losing nearly a thousand men in seventy-six hours. The lesson learned by Colonel James Riseley of the 6th Marine Regiment was that courage was not enough; they needed better intelligence. Riseley authorized a specialized platoon that could kill silently, steal intel, and survive in the jungle without support.

Tachovsky found his recruits in the punishment details. When two Marines brawled, the loser went to the infirmary, but the winner went to the brig. Tachovsky went to the brig and took the winner. He reasoned that a man with a record for fighting had already proven he could handle himself when the rules of civilization were suspended. He assembled a motley crew: a seventeen-year-old kid, a thirty-four-year-old veteran, a former professional boxer, and a man who had been a bodyguard for a Chicago gangster.

Training at Camp Tarawa in Hawaii had stripped away the veneer of the parade ground. They learned to break necks without a sound and to navigate jungle terrain without disturbing a single fern. They became experts with the M1903 Springfield rifle, fitted with eight-power Unertl scopes, capable of hitting man-sized targets at 600 yards. They also learned to steal—raiding Army depots for better rations and Navy warehouses for gear, earning their nickname. Now, as the ramp of the Higgins boat slammed down into the chest-deep water of Saipan, the training was over.

Into the Green Hell

Tachovsky led his men into the surf. The water around them erupted with machine-gun fire, turning the sea into a frothing mix of white foam and red blood. While the main assault waves bogged down at the seawall under withering mortar fire, the 40 Thieves did what they were trained to do: they moved fast and they moved independent of the main force. By 9:30 a.m., they had pushed 300 yards inland, vanishing into the dense vegetation.

They were ghosts in a green hell, maintaining visual contact through hand signals Tachovsky had invented. At 10:15 a.m., Sergeant Bill Knupple halted the column. Ahead, camouflaged into the side of a ridge, was a concrete pillbox housing a Type 92 heavy machine gun. Its interlocking fields of fire covered the valley floor where the 2nd Marine Division was scheduled to advance that afternoon. If left unchecked, that single gun would slaughter hundreds.

Tachovsky weighed the options. Engaging would compromise their reconnaissance mission, but leaving it would be a dereliction of duty. The decision took thirty seconds. Private Marvin Strombo, carrying a bazooka, maneuvered eighty yards from the slit. One rocket, fired at 10:32 a.m., detonated inside the concrete shell, silencing the crew instantly. The platoon melted back into the jungle before the smoke cleared. When the main Marine force moved through the valley hours later, the ridge was silent.

By noon, they had mapped seventeen Japanese positions—machine gun nests, mortar pits, and artillery observation posts. Tachovsky radioed the coordinates using encoded protocols. Minutes later, the devastating roar of naval gunfire from destroyers offshore obliterated the targets. This was the lethal efficiency Riseley had envisioned: a small team of “criminals” guiding the fist of the United States Navy.

The Tank Battalion

Late that afternoon, deep behind enemy lines near Charan Kanoa, the platoon stumbled upon a nightmare. Hidden under camouflage netting in a dense grove were thirty-seven Type 97 medium tanks. Intelligence had estimated the Japanese had perhaps a dozen tanks on the entire island. Tachovsky was looking at three times that number in a single staging area.

The threat was existential. Japanese doctrine favored night attacks. If these tanks hit the beachhead after dark, they could overrun the supply dumps and push the Marines back into the sea. Tachovsky radioed the coordinates, but the response was grim: naval gunfire was tied up, air support was unavailable, and artillery was still being unloaded. They were on their own for at least four hours.

Tachovsky looked at his men. They had six bazookas and thirty-six rockets. The math was insane—forty men against an armored battalion. He ordered them to prepare for an assault, intending to disable as many as possible. But at 4:25 p.m., the grove came alive with the roar of diesel engines. The Japanese were mobilizing early. Infantry swarmed around the tanks. The window for a surprise hit-and-run had closed.

Tachovsky shifted tactics immediately. Instead of attacking, they would shadow the formation. As the massive armored column rolled toward the coast, the Thieves moved parallel through the jungle, feeding real-time coordinates to headquarters. Because of their intel, the Marines at the beach were able to rush Sherman tanks and bazookas to the front lines.

However, the Japanese commander made a sudden, unexpected maneuver. Instead of hitting the main beachhead, the column turned north, aiming for the fragile seam between the 2nd and 4th Marine Divisions. Tachovsky realized the enemy’s intent: they were going to sever the American force in half.

The Duel in the Dark

Twilight fell, and the chaos of the breakthrough began. As the main Japanese force slammed into the Marine lines, Tachovsky spotted a single Type 97 tank detach from the group. It was navigating a ravine that led directly to the 6th Marine Regiment’s command post. Colonel Riseley and his staff were four hundred yards away, completely exposed and unaware that forty tons of steel was hunting them.

Tachovsky grabbed Private Herbert Hodges, the platoon’s best shot. They sprinted down the slope, racing the tank to an intercept point. The Type 97’s frontal armor was too thick for a guaranteed kill; they needed a side shot. They reached a position thirty yards from the ravine just as the tank rumbled into view. The commander was standing in the open hatch, scanning with binoculars.

Hodges waited. The tank stopped as the commander checked a map. At 7:32 p.m., Hodges fired. The rocket struck the thin armor beneath the turret ring. The shaped charge punched through, detonating the ammunition inside. The vehicle erupted in a catastrophic fireball that illuminated the jungle for three hundred yards.

The explosion had an unintended strategic effect. Nearby Japanese infantry, seeing the massive fireball, assumed they had hit a fortified line and veered away from the command post. The 40 Thieves had saved the regimental command, but the muzzle flash had exposed them. Machine gun fire raked their position. They scattered into the darkness, fighting a running withdrawal through a jungle crawling with enemy patrols.

The Cave Rescue

By the next morning, the cost of the chaotic night retreat became clear. Seventeen men were missing. Search teams went out at dawn. They found Private Donald Evans in a shallow grave, stripped of his dog tags. They found three others who had been captured and bayoneted, their hands tied behind their backs.

But radio contact revealed that five men were trapped alive in a cave system a mile behind Japanese lines. They were pinned down, one suffering from a 103-degree malaria fever, another with dysentery. Tachovsky rejected the slow safety of artillery diversions. He led a six-man team on a rescue mission.

They reached the cave, hydrated the sick, and began the extraction. It was a race against time. Burdened by the sick men, they were intercepted by a twenty-man Japanese patrol. Tachovsky initiated an L-shaped ambush, wiping out the enemy force in seven seconds of blistering violence. But the noise drew every Japanese unit in the sector.

Fleeing toward safety, they were forced into a ravine that ended in a box canyon. Forty Japanese soldiers appeared on the ridges above, pouring fire down into the trap. With ammunition critical and no exit, they seemed doomed. Then, Tachovsky noticed vegetation growing from the rear wall—a sign of water, and a sign of a fissure.

They squeezed through a narrow crack in the rock, dragging the sick men through the dark, claustrophobic passage as the Japanese closed in on the empty canyon behind them. They emerged on the other side of the ridge and scrambled back to American lines, collapsing into safety at 2:23 p.m.

The Bicycle Reconnaissance

After a single night of rest, the platoon was sent back out. Their new objective was the town of Garapan, the island’s administrative capital. Marine planners needed to know if the ruins were fortified.

On the afternoon of June 17, Tachovsky led a five-man team, including Strombo, Mullins, Irazi, and Evans, to the edge of the town. The ruins were crawling with Japanese troops. It was a staging area, not a fortress. Then, Corporal Irazi spotted five Japanese military bicycles leaning against a wall.

In a moment of surreal audacity that defined the unit’s character, Tachovsky ordered his men to mount the bikes. They rode into Garapan in broad daylight, posing as Japanese messengers. For forty-three minutes, the five Marines cycled through the heart of the enemy capital, waving at Japanese officers and memorizing supply dump locations. They were hidden in plain sight, protected only by the sheer brazenness of the act. They exited the town, ditched the bikes in the jungle, and brought back intelligence that unlocked the taking of the city.

The Legacy of the Thieves

When Saipan was declared secure on July 9, the cost of their “criminal” efficiency was tallied. The 40 Thieves had lost twelve men killed and nine wounded—a 56% casualty rate. They were gaunt, hollow-eyed, and suffering from tropical diseases, but they had changed the war. Commanders estimated their intelligence had saved 2,000 Marine lives.

Frank Tachovsky returned home to become the mayor of Sturgeon Bay, Wisconsin. Like many of his generation, he buried the war deep inside him. He never spoke of the pillboxes, the tanks, or the bicycle ride through Garapan. His son only discovered the existence of the “40 Thieves” after finding a footlocker following Frank’s death in 2011.

The men selected from the brig had proven that the difference between a troublemaker and a hero is often just a matter of geography and opportunity. They laid the groundwork for modern special operations forces like the Navy SEALs and Force Recon, proving that a small group of rule-breakers, operating in the shadows, could do what an entire battalion could not.