The case of Shawn Lannon began not with a bang, but with a whisper—and then a stench. What unfolded after a seemingly routine report of missing people in Grants, New Mexico, would soon reveal a horrifying trail of lies, dismemberment, and murder that stretched across the American continent, culminating in a 95-year prison sentence for one of the most calculating and chilling serial killers in recent history. This is the story of how an ex-husband’s betrayal and vengeance led to a discovery so gruesome it shook even hardened police officers, exposed a family’s deepest trauma, and uncovered a claimed death toll far higher than the five confirmed victims.

The nightmare for three families began in late January, with the unexplained disappearances of 21-year-old Matthew Miller, 39-year-old Jennifer Lannon, and her 40-year-old partner, Justin Mada. Jennifer was the ex-wife of Shawn Lannon, the man who would quickly become the centerpiece of the police investigation. As the weeks dragged on, concern turned to dread. Jennifer’s mother, calling from New Jersey, noted her daughter’s unusually long silence—three weeks without a text or call—a behavioral anomaly that screamed foul play.

The Web of Lies and the Missing Truck

The focus of the investigation soon narrowed onto Shawn Lannon, the father of Jennifer’s three children. In initial interviews, Shawn, while maintaining a façade of cooperation, painted a picture that was immediately suspicious. He claimed Jennifer had run off with Justin and a mysterious third man, frequently returning to collect belongings. He also admitted to driving Matthew Miller’s truck weeks prior to the disappearance, but lied about where and when he parked it.

Veteran detectives quickly realized they were dealing with a master manipulator. Surveillance video directly contradicted Shawn’s timeline, showing him driving Matthew’s truck a month later than he claimed, parking it at the Leach Apartments, and walking away. Furthermore, Lannon was exposed for visiting a rumored girlfriend, Kelly, just before a police interview, where he stashed a bag containing a gun and Jennifer’s IDs. The destruction of Jennifer’s phone, witnessed by Kelly, was a clear attempt to sever a vital investigative link. Detective Turney’s confrontation of Lannon in the interrogation room was blunt and direct: “The things that you’ve told us, I’ve completely ruled each one of them as just an outright lie,” he stated.

The investigative suspicion became a horrifying reality on March 5th, when the focus shifted to an airport parking garage in Albuquerque. Security officers there had noted a foul smell emanating from a red Ford Ranger pickup truck. Upon investigation, police discovered multiple storage totes inside the truck and its cab. The contents were ghastly: dismembered body parts. All three missing individuals from Grants—Jennifer Lannon, Justin Mada, and Matthew Miller—were accounted for among the remains, stuffed into containers alongside bloody hand tools.

The Fifth Victim and the Chilling Confession

The macabre discovery contained a fourth body, initially unidentified. The victim was later identified as Randall Apostlon, the registered owner of the truck. His death, caused by significant blunt force trauma, completed the tableau of violence.

Just before the truck discovery propelled the case into the media spotlight, Shawn Lannon had boarded a flight to New Jersey with his three children, having secured their tickets through his mother. For a brief moment, he was out of New Mexico’s jurisdiction, but his spree was not over. Only two days after the truck was found, a welfare check was requested at the East Greenwich Township home of Michael Dubcowski, a 66-year-old man who had served as Shawn Lannon’s “Big Brother” mentor for years.

Police found Dubcowski bludgeoned to death in his garage. The link was undeniable: the last person Michael Dubcowski’s friend could think of was Shawn Lannon. With the fifth murder committed, Lannon’s flight ended in St. Louis, Missouri, where U.S. Marshals apprehended him in Dubcowski’s stolen car, finding a hammer and bloody clothing inside.

Finally in custody, Shawn Lannon was ready to talk, and his story was bizarre, vengeful, and self-serving. He confessed to all five murders, presenting shocking justifications for the New Mexico victims.

Jennifer Lannon: Shawn claimed he returned home to find his three children unresponsive, allegedly drugged by Jennifer and Justin with either a substance in their medicine or heroin smoke. Shawn asserted that Jennifer confessed to him that she had “killed the Garrison baby” in a prior overdose incident. He claimed he executed her with a pistol to the back of the head as she was succumbing to a self-administered heroin overdose, all while repeating the emotionally charged statement, “you killed the Garrison baby.”
Justin Mada and Matthew Miller: Shawn lured Justin back to the house by impersonating Jennifer in text messages. He claimed that Justin, and later Matthew, were killed because they were involved in taking and sharing explicit photos of his son. Lannon claimed he shot Justin in the back of the head in the laundry room after Justin looked in a vent for heroin. Matthew, he claims, was shot in the garage after the same question about the photos.
Randall Apostlon: The owner of the truck was killed purely out of self-preservation. Shawn admitted to killing Randall after the man saw the bodies in the totes and threatened to expose Lannon unless he was paid an additional $300. Shawn bludgeoned Randall with the sledgehammer and then hid the body under the passenger seat, showing astonishing coolness when police arrived only minutes later on an unrelated warrant.

The horror extended beyond the killings. Shawn described the “awful and traumatic” process of dismembering the victims to fit them into the storage bins, often at night while his children were asleep in the house. He recounted how he had to “work up the nerves” to move the bodies and even revealed details like having to “displace the socket on his hip” on one of the victims. He claimed to have planned the crime, laying down plastic and tarps, bragging, “I’m not the dumbest guy.”

The Unproven Ghosts and the Final Sentence

The New Jersey murder of Michael Dubcowski, Shawn’s former “Big Brother,” was justified by Lannon as an act of vengeance for alleged sexual abuse he endured as a child. He claimed to have demanded and received the explicit pictures, which he then burned. However, this claim remains unverified. Dubcowski was a respected community figure, named “Big Brother of the Year” in 1985. Those closest to Lannon, including the children’s nanny, expressed skepticism about the allegation, noting that Mike was a constant, supportive figure in Shawn’s life.

Perhaps the most chilling revelation of all was Lannon’s claim that the five confirmed murders were merely the tip of the iceberg. He told investigators that he had killed 11 other people in the years prior to 2021, hiding their remains in the lava tubes at the El Mal Pais National Monument in New Mexico. He vaguely attributed these killings to protecting Jennifer from people looking for drugs or money. While Lannon offered different, inconsistent stories about how he found the lava tubes or how he disposed of the bodies—including an outrageous claim of using acid in a plastic tank—police remain skeptical, as no missing persons reports or bodies have been linked to his story.

His mother suggested that Lannon’s psychological state was shattered by his military service in Kosovo, where he witnessed “violent mass grave ethnic cleansing,” claiming he saw things that made him believe “there could be no God.”

In the end, Shawn Lannon avoided a first-degree murder trial by agreeing to a plea deal. He was sentenced to 35 years for the murder of Michael Dubcowski in New Jersey and 60 years for the four New Mexico murders (plead down to second-degree), resulting in a staggering total of 95 years behind bars.

The ultimate tragedy is the fate of the three children, who were caught in the very center of their parents’ violent storm. They have since been adopted by Jennifer’s brother, Christopher, left to live with the knowledge of the immense, senseless violence that claimed their mother and stepfather at the hands of their own father. The haunting question of whether Shawn Lannon’s motives were rooted in self-defense, revenge, or pure, premeditated violence remains a dark stain on the lives of everyone touched by his unspeakable crimes.