Long before the Zodiac and the Son of Sam, there was 3X, The Man Behind the Gun. He killed with a mysterious agenda, communicated in ciphers, and claimed to be part of an international cabal of anti-communist operatives. For one long summer in 1930, he held New York City in thrall.
It began on June 11, 1930, on a secluded lover’s lane near the College Point neighborhood. Joseph Mozynski, a 39-year-old grocery store owner, and his 19-year-old mistress, Catherine May, had just settled into their clandestine rendezvous when a stranger approached. He was short, slight of build, and spoke with a thick German accent. The man seemed to recognize Mozynski, as though he had been searching for him. Without hesitation, he pulled a gun and shot him twice in the head. As Mozynski slumped lifelessly in his seat, the killer rifled through his pockets, extracting some papers—documents he appeared to be looking for—which he promptly set on fire.
May later claimed that the man forced her out of the car and raped her. Afterward, he demanded her address and walked her to a bus stop. As she boarded, he handed her a small, folded piece of paper, warning her not to read it until the next day. He rode the bus with her for several stops before disembarking. Ignoring his instructions, May unfolded the note. Stamped in red ink, it read:
“Joseph Mozynski 3X 3-X-097”
Yet, curiously, May did not report the murder. Investigators found her jacket in Mozynski’s car and tracked her down. Her silence and inconsistent statements immediately raised suspicion. She was interrogated for three days, giving multiple conflicting versions of her story, including one in which a local mob figure was the culprit. It was soon revealed that she and Mozynski—who was married with two children—had been involved for over two years, a secret she may have been desperate to conceal.
Three days later, while May remained in custody, a bombshell arrived in the form of a letter sent to the New York Evening Journal:
“Kindly print this letter in your paper for Mozynski’s friends: “CC-NY ADCM-Y16a DQR-PA . . . 241 PM6 Queens.”
By doing this, you may save their lives. And the women may know where the missing papers are and who has them since they were given to Mozynski. We do not want any more shooting unless we have to.
3X, The Man Behind the Gun”
The letter had been postmarked before Mozynski’s body was even discovered. Combined with May’s story, there was little doubt—it was written by the killer. The Evening Journal published a story that evening about the murder but did not include the message from 3X.
The following day, another letter arrived:
“Gentlemen,
For your information, the young lady, Miss C. May, involved in this case is innocent and a victim of unfortunate circumstances. Mozynski was nothing but a rascal—a dirty rat. Not two women as stated in the papers, but six, and two young girls, one 14 and one 15, were with him in that same place.
I am the agent of a secret international order, and when I met Mozynski that night, it was to retrieve certain documents from him. Unfortunately, they were not in his possession.
If his relatives knew of his luck with women, perhaps they could tell us what became of the following items: NYX-26-73; NJ 4-3-44; Philadelphia XV 346. These papers must be returned to us at once, or 14 more of Mozynski’s friends will join him.
Mozynski’s relatives and friends have until Monday at 12:00 PM to bring these documents to us—or to inform us where to find them. If no answer is received, we will start merry hell for all of them.
3X, The Man Behind the Gun”
Beneath the signature was an unusual symbol—an inverted letter “V” atop a right-side-up “V.”
3X did not wait long to make good on his threat.
On June 16, Noel Sowley, a 26-year-old radio mechanic, and his girlfriend, Betty Ring, 18, were parked in a secluded spot near a salvage yard in Floral Park when they were startled by a man with a flashlight. He spoke with a thick German accent, shining the beam directly into their eyes as he asked Sowley for his driver’s license. Then, using the flashlight, he signaled in a Morse Code-like pattern, claiming he was communicating with an unseen accomplice.
The man asked Sowley if he knew Joseph Mozynski. When Sowley answered that he did not, the stranger shot him in the mouth. Gasping through his wound, Sowley pleaded that he wasn’t the person the killer was looking for. Unmoved, the man walked to the rear of the vehicle, inspected the license plates, and returned.
“You’re the one we want, all right, and you’re going to get what Joe got.”
With that, he shot Sowley in the head, killing him instantly.
As with Mozynski, the killer searched Sowley’s pockets. Upon finding a particular document, he murmured, “I have it!”
Ring later claimed that he attempted to assault her but was deterred by her pleas and the religious symbol she wore around her neck. As before, he walked her to a bus stop, rode with her for several stops, and handed her a note, instructing her not to read it until the next day. When she unfolded it, she found the same ominous message as before:
“Sowley 3X”
The evidence left behind confirmed the murders were linked. Ballistic analysis proved the bullets that killed Mozynski and Sowley came from the same weapon. A newspaper clipping about the Mozynski murder was found in Sowley’s pocket, marked with the chilling annotation:
“Here’s how.”
A roll of cash, tucked between the pages of a blood-stained magazine, further deepened the mystery.
The next day, another letter from 3X arrived—this time containing two spent shell casings from the Sowley murder. It was addressed to police officials:
“Inspector J. J. Gallagher, Lieutenant J. Smith,
For your information, one more of J. Mozynski’s friends was sent to meet him. V-5 Sowley was shot to death near Floral Park—not very far from a police signal station.
I enclose the two empty shells. Some of our money was found on his person, along with the N.Y. document.
The girl, as in the case of Miss May, was put aboard a bus and sent home—but no clues were left for you this time. Thirteen more men and one woman will go if they do not make peace with us and stop bleeding us to death.”
And on the morning of June 18, an even more ominous note arrived at the Journal:
“Tonight, one more will go. You may let them know—3X is the man behind the gun.
He asks for no quarter and will give none.
On June 18 at 9:00 PM, I will be at College Point to get WR V-8.”
Understandably, the entire city was on edge. Police were out in extra force, lovers’ lanes stood abandoned, and mothers kept their daughters home. Yet, despite his previous pattern, 3X did not strike again that night. Instead, he surfaced in Philadelphia, where he mailed another of his cryptic letters—this time addressed to John Mozynski, the brother of his first victim. The letter demanded that Mozynski deliver a collection of “stolen” documents, instructing him to leave them at Broad Street Station. However, Mozynski claimed no knowledge of these documents and was subsequently placed under police protection.
Then, on June 21, 3X sent his most intriguing letter yet, once again addressed to the Evening Journal:
“Dear Sir: The last document, N.J. 4-3-44, returned to us the 19 at 9 p.m. My mission is ended. There is no further cause for worry. I do not know Doctor Williams and the others. The first sign means A, the supreme tribunal of the order. The second, V, its special agent. The two combined form the Red Diamond of Russia, a secret organization all over the world. Anyone breaking its rules is marked for death. These men were dismissed for treason. They were all our friends but came in contact with a gang of blackmailers and a drug ring and turned against us. One of them stole the documents mentioned before and they tried to use them for blackmailing our men here. Most of us are soldiers and every nation in the world is represented in our ranks.
Word came to us at the supreme council in Russia of the peril in the U.S. Twelve of us picked one card. Mine was the king of diamonds. I was the one selected to punish and inflict death if necessary. I have patiently waited. I have warned them all of danger. Instead of heeding the warning, they answered me by blackmail. They were requested many times for the return of the papers but refused to surrender them. It was when Mozynski died that they found out who I am. Now it is all over. The documents in question—one is a military document, another is political, and the third one just surrendered is commercial. Who am I? Not much. An ex-German Army officer of the Wilhelm St. Office, Berlin, during the war. Now in the service of the Red Diamond of Russia. Yes, the code was addressed to Sowley. Now it is all over. You show me to be brave. Any man who took orders from this 77 is fearless. Your policemen are brave men, only they need training. I was watching them at C.P. on the 18th at 9 sharp.
A German officer never breaks his word—yes, right there. Have you heard a plane? It was a monoplane, small, very fast. The plane circled twice over Flushing, C.P. Bayside, then went away. If you did, then you will know I was there…. I have no fish eyes. The police have fish eyes. … They have always been wrong from beginning to end. That is why they have lost from beginning to end. For two reasons. One I have stated to you. The other, they are too slow.
I am deeply sorry for having stained your country with blood, but let this be a warning to all concerned—treason of one word means death. The next time, no mercy will be shown. Death only will be the penalty, but I hope I will not be the one to inflict it next time. We are not maniacs or bandits or robbers—robbery never was the motive, and we do not belong to any dope ring. This is final. You know what we want you to know. Quiet your people and tell them that 3X is no more.
H.P. 12W. A.
Do not let anyone fool you. If any more letters come, they are fakes. I am leaving today on my way back to Russia. Please note I do not write USSR. We do not recognize them. There is no one else to begin trouble. It is settled.
H.P. 12W. A.
Though countless imposters and copycats attempted to claim the 3X moniker by sending letters in his name, no further communications were ever confirmed to be from the real killer. Nor were there any additional murders. Of course, this did little to assuage the panicked citizens of New York, and the police continued their investigation long after the trail had gone cold.
So, who was 3X? Was he truly an agent of a clandestine order, a delusional maniac, or something else entirely? Let’s examine the theories.
The Secret Agent Theory
Could 3X have been a member of an underground anti-communist resistance? There’s no historical record of the “Red Diamond of Russia” outside of these murders, making it unlikely such a group ever existed—at least as described. For a supposedly secretive organization, 3X was remarkably loose-lipped, weaving a narrative straight out of a pulp thriller. His coded messages remain untranslated, and his final letter is a mess of grandiose claims, including watching police from a small aircraft. Then there’s his insistence on closing the book on his own story, even announcing his travel plans. A genuine operative would not seek this kind of attention. The spy story? Highly doubtful.
The 3X Copycats
Even after the murders stopped, 3X lingered in the public imagination. Two years later, during the infamous Lindbergh baby kidnapping, some linked 3X to the crime, claiming Bruno Hauptmann was part of a larger conspiracy. The theory hinges on Lindbergh’s alleged Nazi sympathies and the idea that the “Red Diamond” could have targeted him, but there’s no evidence tying 3X to the case.
In 1937, a couple was found murdered on a lover’s lane, their foreheads marked with red circles, again reviving memories of 3X. While the so-called “Red Circle Slayings” were never solved, there’s little to suggest a real connection beyond speculation.
The Serial Killer Theory
From a modern perspective, 3X exhibits classic traits of a serial killer—taunting letters, a need for control, and an inflated ego. His letters, elaborate persona, and adversarial relationship with law enforcement resemble those of infamous killers to come. However, some aspects of his crimes don’t align neatly with the serial killer profile. His methods, motivations, and erratic behavior complicate the analysis.
The Catherine May Theory
A more provocative possibility: What if Catherine May wasn’t a victim, but a participant in Joseph Mozynski’s murder? It’s a controversial idea, but some details warrant scrutiny.
May never reported the murder or her assault—a strange omission. When first interrogated, she gave conflicting accounts, naming a former lover and a known mobster before settling on the story we know. The first 3X letters appeared while she was still in custody. Only after Betty Ring’s testimony did police drop her as a suspect, despite their descriptions of the killer differing wildly—May’s was a short, middle-aged German man, while Ring’s was a tall, lanky man in his 30s.
Then there’s the second letter, written on stationery from May’s workplace. It goes out of its way to exonerate her while vilifying Mozynski, portraying him as a serial philanderer, even with minors. Nowhere does it mention her alleged assault—odd, considering 3X’s supposed moral justifications.
Perhaps most bizarre is 3X’s behavior after the crime. He didn’t just let May go—he escorted her to a bus stop and even rode with her for several stops. It’s an unnecessary, reckless risk for a man supposedly trying to disappear.
What if May, angry at Mozynski over a failed affair, arranged the killing with an accomplice? The gunman shoots Mozynski, but May, rattled, flees, accidentally leaving behind her coat—the very clue that led police to her. If she hadn’t, would anyone have known she was there at all?
The second murder, that of Noel Sowley, may have been staged to solidify the 3X persona and shift suspicion away from May. The killer simply followed the blueprint laid out in her testimony. The theatrics at the scene, like taking Sowley’s license, seem designed more to bewilder police than to serve a real purpose. Ring was approached but not harmed—likely because she wasn’t meant to be a victim, just a witness to add credibility.
May could have known about Mozynski’s brother in Philadelphia, allowing the killer to further the deception by reaching out to him. The dramatic finale—threats, coded messages, then a sudden disappearance—suggests a need to close the case rather than an actual ideological mission.
After nearly a century, the case of 3X remains an enigma. Was he a cunning killer playing a long game of deception, a delusional figure lost in his own fantasies, or something else entirely? Theories abound, but hard evidence is scarce, leaving us with only fragments of a story that may never be fully understood. What we do know is that 3X was more than just a murderer—he was a storyteller, shaping his own legend in ink and blood.
Jason Roberts is a Seattle-based author noted for his acclaimed western horror series The Dead Wind Trilogy as well as other works of cosmic horror infused with historical fiction. His web-based series, Dark Distractions examines paranormal mysteries, unexplained phenomena, and all things strange.
