Our Arklahoma Heritage: Camp Gruber served as "courthouse" for five Nazi POW's who killed a "spy" among them

Located in the rolling Cookson Hills near Braggs in Muskogee County, Camp Gruber has long been a place of layered history--a sprawling military training ground where sweat, camaraderie, and sacrifice shaped its identity.

Established in 1942 to prepare American soldiers for World War II, the 60,000-acre base buzzed with the energy of tank maneuvers and rifle drills. Yet, beneath the surface of its proud legacy lies a darker chapter that still lingers in the memories of Muskogee County’s old-timers: a secretive 1943 court-martial that saw five German prisoners of war face justice for a brutal murder.

Camp Gruber’s role as a POW camp is less celebrated than its training grounds, but during World War II, a section west of Highway 10 housed thousands of captured German soldiers.

Most were conscripts or Afrika Korps veterans, men who found themselves far from the battlefields of Europe, confined behind barbed wire under the Oklahoma sun.

The camp’s POW population, peaking at over 4,000, was generally orderly, with prisoners assigned to labor projects--building roads, digging drainage canals, and even crafting stone monuments that still dot the landscape. But in 1943, a shocking crime shattered the routine.

The incident traced back to another facility, the Tonkawa POW camp in northern Oklahoma.

There, on November 4, 1943, a German prisoner named Johannes Kunze was beaten to death by his fellow captives. Kunze, a 33-year-old soldier, was suspected by his peers of disloyalty to the Nazi cause

. Some whispered he’d shared information with American guards; others claimed he criticized Hitler’s regime too openly. Whatever the truth, his death was savage--struck with fists, boots, and makeshift weapons in a barracks attack that left him lifeless on the floor.

Five prisoners were accused of the murder: Werner Ulrich, Rudolf Straub, Horst Günther, Hans Demme, and Berthold Seidel. All were young, battle-hardened men in their 20s, loyal to the German military code and, for some, to the ideology that fueled it.

Because Tonkawa lacked the facilities for a high-profile tribunal, the case was transferred to Camp Gruber, where a military courtroom could be secured under tight control. The decision wasn’t random--Gruber’s isolation and infrastructure made it ideal for containing a case that carried explosive potential.

The trial was held in a nondescript military building near the camp’s administrative core, a single-story structure with bare walls and wooden benches. Military police stood guard outside, their M1 rifles glinting in the summer heat, ensuring no curious locals or reporters wandered too close.

Details of the trial remain scarce, as wartime secrecy buried much of the record. What is known comes from fragmented military archives and oral histories pieced together by researchers.

UniversityArmy officers, likely led by Colonel James A. Kilian, who oversaw Gruber’s POW operations at the time. The prosecution argued that the five defendants had conspired to kill Kunze as an act of vigilante justice, enforcing a brutal code of loyalty among prisoners.

Testimony painted a chilling picture. Fellow POWs, coerced or willing, described how Ulrich and Straub organized the attack, singling out Kunze after weeks of suspicion. Günther and Demme, both former infantrymen, were accused of delivering the fatal blows, while Seidel stood watch, ensuring no one intervened.

The evidence included bloodied clothing, a broken chair leg used as a club, and Kunze’s autopsy report, which detailed fractured ribs and a shattered skull. The defense, represented by appointed Army lawyers, argued the men acted under duress, caught in a web of fear and group pressure. But the tribunal was unmoved.

On September 10, 1943, all five were found guilty of murder. Their sentence: death by hanging. The verdict was kept under wraps, with no press releases or public statements. The men were transferred to Fort Leavenworth, Kansas, where, on July 10, 1945, they were executed in the military prison’s gallows.

Straub is alleged to have said just before his execution: "What I did was done as a German soldier under orders. If I had not done so, I would have been punished when I returned to Germany".

Their bodies were buried in unmarked graves on the post, a final erasure of their story.

For the people of Muskogee and Braggs, the trial was a shadow on the edge of daily life. Camp Gruber employed hundreds of locals--mechanics, cooks, drivers--who saw the comings and goings of military brass but rarely the POWs themselves.

Still, rumors spread like wildfire. At the Muskogee diner on Okmulgee Avenue, now long gone, farmers and shopkeepers swapped theories over biscuits and coffee. Some said the murdered prisoner was a traitor; others thought the Germans were just restless, itching for a fight.

Churchgoers at First Baptist whispered about the morality of it all—could men so far from home be judged by American laws? The secrecy only fueled curiosity, but with the war raging, most folks turned their focus to ration books and victory gardens.

The German POWs left more than rumors at Camp Gruber. Their labor shaped the land in ways that endure. Along the camp’s western edge, brick-lined drainage canals, built with Teutonic precision, still channel rainwater after decades of storms.

Near the main gate, off Highway 10, stand two stone monuments--a carved bench and a low pillar--crafted by prisoners in 1944. The stones bear no names, only the faint chisel marks of men who worked under guard but took pride in their skill.

Today, Camp Gruber is quieter, a training site for the National Guard and a haunt for historians chasing its stories. The courtroom building is gone, replaced by modern barracks, but the canals and monuments remain, inviting questions from hikers and hunters who stumble across them. For locals the court-martial is a reminder of a time when war touched their backyard, bringing not just soldiers but secrets, too.

As the sun sets over Gruber’s oak-dotted hills, the whispers persist, carried by the wind through a place that holds its past close, reluctant to let it go.