Mark Seifert Missing Person Case

Mar 09, 2011

Jun 07, 2022

Mark

Seifert

73

31

71 inches

145 lbs

White / Caucasian

Male

On a cold day in February 1984, the life of 32-year-old Mark Anthony Seifert took a turn that would leave his family with decades of unanswered questions. He was last seen in Machias, New York, on February 13, 1984, reportedly on his way to what he believed was a promising business meeting. This meeting, however, was a fabrication, a crucial part of a sinister plot. The discovery of Mark's vehicle, a Lincoln Continental, engulfed in flames on a desolate rural road in Cattaraugus County, signaled a tragic end to his journey. Near the burning car, investigators found two pools of blood, along with bone fragments and what appeared to be brain tissue, grim evidence suggesting a violent encounter. Despite the alarming scene, Mark Seifert was nowhere to be found, thus beginning a long and complex investigation into his disappearance. The investigation into Mark's vanishing soon focused on his own family, specifically his older brother, William Seifert. It was revealed that William had orchestrated the fake business meeting, enlisting a waitress to pose as a secretary for a fictional company called Tri-State Developers. This woman contacted Mark, luring him to the remote location with the promise of a lucrative construction project. The motive behind this elaborate deception appeared to be a deep-seated animosity William held towards his younger brother. This hatred allegedly stemmed from family disputes and Mark's homosexuality. The situation had escalated to the point where Mark had filed criminal charges against William, with a pending court date that William was reportedly desperate to avoid. A chilling statement was later attributed to William by his twin brother, who testified to hearing him say, "It will never get to Court; I will kill the bastard first." Despite the lack of a body, the circumstantial evidence against William Seifert was compelling enough for prosecutors to move forward with a murder charge. The case built by the prosecution painted a picture of a premeditated murder, meticulously planned and executed by a brother. Key evidence included the testimony of the waitress who made the decoy phone call, fibers from William's van matching those found at the scene, and the discovery of human blood in his vehicle. In a unique and challenging legal case, William Seifert was convicted of second-degree murder, a verdict reached without the discovery of his brother's remains or a confession. To this day, Mark Seifert's body has never been located, leaving a painful void for his loved ones. The case remains a somber story of familial betrayal and a murder conviction based entirely on circumstantial evidence, a testament to the investigators and legal teams who sought justice for Mark.

Feb 13, 1984

Machias

New York

Cattaraugus County

9779

New York State Police - Machias

Machias

New York

Cattaraugus County

14101

9761 New York 16, New York

7163534029

State

Law Enforcement

SJS 3029407

New York State Police - Machias

Brown

Brown

Brown

09/11/2026