Missing Man’s Body Was Found on Sidewalk in Another State. Over 20 Years Later, His Body Is Identified

Decades-Long Mystery Solved: Man Found Unconscious in Another State Finally Identified

In a long-awaited resolution to a decades-old case, an Ohio man who was found unconscious on a sidewalk in Phoenix has finally been identified after more than 20 years. John Thiellesen, who went missing in 2004 and was later found unresponsive in Arizona before passing away, has now been identified, bringing closure to his family and authorities.

John Thiellesen, a 42-year-old man from Ohio, was reported missing by his brother in 2004. The Toledo Police Department revealed in September 2023, as part of its “Still Missing” campaign, that John had called his sister indicating his intentions to “cleanse” himself by jumping into the Maumee River, which flows into Lake Erie. This marked the beginning of a mysterious disappearance that would remain unsolved for over two decades.

It wasn’t until March 2025 that the pieces of the puzzle started to come together. With the aid of investigative genetic genealogy, the Maricopa County Office of the Medical Examiner in Arizona was able to confirm the identity of a long-unidentified John Doe as John Thiellesen. The collaboration between the medical examiner’s office, authorities, and partners such as the Ramapo College of New Jersey was crucial in this breakthrough.

Following his disappearance, John Thiellesen was discovered alive but unconscious in Arizona, only to be declared dead at a hospital in August 2004 without any identification on his person. The circumstances surrounding how he ended up in Phoenix remained shrouded in mystery. Even the Phoenix Police Department’s efforts to identify him using fingerprinting and DNA proved futile at the time.

In 2024, a turning point came when the medical examiner’s office teamed up with the Investigative Genetic Genealogy Center at Ramapo College and two laboratories. Through the identification of two of Thiellesen’s third cousins, a DNA sample was eventually obtained from one of his siblings, leading to his positive identification. This collaborative effort yielded the much-awaited closure for John’s family and friends.

Arizona Attorney General Kris Mayes commended the tireless work of the Cold Case Unit in bringing solace to families like the Thiellesens. The use of advanced technology and inter-agency cooperation has proven to be instrumental in resolving long-standing cases, offering hope to those still seeking answers about missing and murdered loved ones.

As the details of John Thiellesen’s story come to light, it serves as a poignant reminder of the importance of never giving up on missing persons cases. The dedicated efforts of law enforcement agencies, forensic experts, and genealogists highlight the power of collaboration in pursuing justice and closure for families affected by such tragedies.

In the quest for resolution and closure in cold cases, the identification of John Thiellesen stands as a testament to the perseverance and dedication of those involved in unraveling the mysteries of the past. Through the support and advancements in investigative techniques, more families may find the answers and closure they have been seeking for years.

The discovery and identification of John Thiellesen’s remains symbolize a chapter of closure in a tale that has spanned over two decades. While questions may still linger about the events leading to his tragic end in Phoenix, the resolution brings a sense of peace and finality to those who have mourned his loss for so long.