Sean Michael Lannon: Murders in New Mexico and New Jersey
Overview
Sean Michael Lannon is an American serial killer convicted of murdering five people during a violent crime spree that stretched from New Mexico to New Jersey in early 2021. His victims included his former wife, three men connected to the community around Grants and Albuquerque, New Mexico, and a former youth mentor living in New Jersey. The investigation began as a series of missing-person cases but expanded into a multistate manhunt after four bodies were discovered inside a vehicle at an airport parking garage.
Lannon later claimed that he had killed as many as sixteen people, including eleven alleged drug dealers in New Mexico. Investigators examined those statements, but authorities did not publicly confirm the additional killings. The five murders for which he was convicted remain the only deaths conclusively attributed to him through criminal proceedings.
The New Mexico Disappearances
Jennifer Lannon, Sean Lannon’s former wife, disappeared from Grants, New Mexico, in January 2021. Two men from the same area, Jesten Mata and Matthew Miller, were also reported missing during that month. The disappearances initially appeared to be separate cases, but investigators gradually uncovered connections among the missing individuals and Sean Lannon.
According to the prosecution’s reconstruction of the crimes, Lannon killed Jennifer Lannon, Jesten Mata and Matthew Miller in or near Grants. Evidence presented during the investigation indicated that some of the victims’ bodies were dismembered. Authorities believed Lannon then enlisted or forced another man, Randal Apostalon, to help place or transport the remains in a pickup truck.
Apostalon was subsequently killed in Albuquerque. Investigators concluded that Lannon murdered him after the other three victims were dead, possibly to prevent Apostalon from revealing what he knew about the killings and the movement of the bodies.
Discovery at Albuquerque International Sunport
On March 5, 2021, airport security personnel investigated a strong odor coming from a pickup truck parked on the upper level of the parking garage at Albuquerque International Sunport. Inside the vehicle, authorities found the bodies of four people. They were identified as Jennifer Lannon, Jesten Mata, Matthew Miller and Randal Apostalon.
The discovery brought the earlier missing-person investigations together and immediately turned the case into a quadruple-homicide investigation. Three of the victims had been missing since January, meaning their bodies had apparently been concealed for weeks before being left at the airport. The condition of the remains complicated efforts to determine an exact date of death for each New Mexico victim.
Investigators determined that Jennifer Lannon, Mata and Miller had most likely been killed in Grants during January 2021. Apostalon was believed to have been murdered in Albuquerque during February 2021. Public records have not established a verified exact calendar date of death for any of the four New Mexico victims.
Victims
- Jennifer Lannon, 39: Jennifer Lannon, also identified by her maiden name of Jennifer Whitman, was Sean Lannon’s former wife and the mother of their children. She disappeared from Grants, New Mexico, in January 2021. Investigators concluded that she was killed in Grants during that month, although an exact date of death was not publicly established. Her remains were discovered inside the pickup truck at Albuquerque International Sunport on March 5, 2021.
- Jesten Mata, 40: Jesten Mata was reported missing from the Grants area in January 2021. Authorities determined that Lannon killed him in Grants during that month. Evidence indicated that Mata was among the victims whose remains had been dismembered before being placed in the vehicle. His exact date of death was not publicly determined. His body was found at the airport on March 5, 2021.
- Matthew Miller, 21: Matthew Miller disappeared from the Grants area in January 2021. Investigators concluded that Lannon murdered him in Grants during the same general period as Jennifer Lannon and Jesten Mata. An exact date of death was not publicly established. Miller’s remains were recovered from the truck at Albuquerque International Sunport on March 5, 2021.
- Randal Apostalon, 60: Randal Apostalon was believed to have been involved in loading or transporting the remains of the other New Mexico victims. Prosecutors alleged that Lannon later killed Apostalon in Albuquerque, apparently after Apostalon had assisted with the truck. Authorities placed his death in February 2021, but no verified exact date was publicly released. His body was discovered with the other victims on March 5, 2021.
- Michael Dabkowski, 66: Michael Dabkowski was killed on March 8, 2021, inside his home in East Greenwich Township, Gloucester County, New Jersey. Dabkowski had known Lannon and his twin brother through a youth-mentoring relationship when they were children. Lannon admitted striking Dabkowski repeatedly with a hammer. After the killing, Lannon stole Dabkowski’s vehicle and fled New Jersey.
The Murder of Michael Dabkowski
Only three days after the four bodies were discovered in Albuquerque, police conducted a welfare check at Michael Dabkowski’s home in East Greenwich Township, New Jersey. On March 8, 2021, officers found Dabkowski dead inside the residence. He had suffered severe blunt-force injuries after being attacked with a hammer.
Lannon later admitted that he went to Dabkowski’s home after unsuccessfully attempting to enter other residences in the area. He claimed that Dabkowski had sexually abused him during childhood, an allegation that became part of Lannon’s explanation for the murder. Regardless of the alleged history between them, prosecutors maintained that Lannon intentionally killed Dabkowski, stole his automobile and fled across several states.
Authorities issued alerts for both Lannon and the stolen vehicle. He was captured on March 10, 2021, in St. Louis, Missouri. At the time of his arrest, he was driving Dabkowski’s vehicle. Investigators also recovered the hammer believed to have been used in the murder.
Claims of Additional Murders
After his arrest, Lannon made the startling claim that he had killed sixteen people. According to statements described during a New Jersey court hearing, he said that fifteen of the victims had been killed in New Mexico and that Dabkowski was the sixteenth. He reportedly claimed that eleven of the New Mexico victims were drug dealers whom he had lured to a residence before killing and dismembering them.
Law-enforcement agencies investigated the statements with assistance from federal authorities. Investigators searched locations connected to Lannon and reviewed missing-person and homicide cases that might have matched his account. However, officials expressed skepticism about the truthfulness of his claims, and no evidence was publicly announced that conclusively tied him to eleven additional victims.
Because the unsupported claims were never proven in court, Lannon is considered responsible for five confirmed murders rather than sixteen. His statements nevertheless raised concerns that other victims might exist and added another disturbing dimension to an already complicated investigation.
New Jersey Conviction and Sentence
Lannon was prosecuted first in New Jersey for the murder of Michael Dabkowski. In October 2022, he pleaded guilty to murder. During the proceedings, he admitted that he intentionally struck Dabkowski with a hammer and took his vehicle.
In December 2022, a New Jersey judge sentenced Lannon to thirty-five years in state prison. Under the terms of the sentence, he must serve the large majority of that term before becoming eligible for parole. The conviction formally established his responsibility for Dabkowski’s death while the New Mexico prosecution remained pending.
New Mexico Guilty Pleas
After the New Jersey case was resolved, Lannon was returned to New Mexico to face charges connected to the four bodies found at Albuquerque International Sunport. The prosecution originally pursued first-degree murder charges, but the case was ultimately settled through a plea agreement.
In May 2024, Lannon pleaded guilty to four counts of second-degree murder for killing Jennifer Lannon, Jesten Mata, Matthew Miller and Randal Apostalon. He received four consecutive fifteen-year prison terms, producing a combined New Mexico sentence of sixty years.
The sixty-year sentence was ordered to follow his thirty-five-year New Jersey term. Together, the sentences amount to ninety-five years of imprisonment. The arrangement means Lannon is expected to remain incarcerated for the rest of his life.
Significance of the Case
The Sean Lannon case crossed multiple jurisdictions and began with several people disappearing from a relatively small New Mexico community. The discovery of four bodies more than seventy miles away in an airport parking garage exposed a calculated effort to conceal the victims and delay identification of the crimes.
Lannon’s flight to New Jersey and the murder of Michael Dabkowski transformed the investigation into a nationwide search. His arrest in Missouri connected the stolen vehicle, the suspected murder weapon and the suspect sought in both states. Cooperation among local police departments, prosecutors, federal investigators and agencies in several states was essential to tracing his movements and securing the convictions.
Although Lannon claimed responsibility for many more deaths, the criminal cases proved that he murdered five people between January and March 2021. Jennifer Lannon, Jesten Mata, Matthew Miller, Randal Apostalon and Michael Dabkowski were ultimately identified as the confirmed victims of a brief but exceptionally destructive multistate killing spree.
