Man Found On Sidewalk Is Identified Thanks To North Jersey Students

MAHWAH, NJ — A "John Doe" who was found unconscious on a Phoenix sidewalk in 2004 had a name, and it actually was John. But he didn't have ID on him, and he lay in a hospital unidentified for more than a week before he died.

More than two decades later, his family has answers thanks to students and staff at a Mahwah-based college.

The Ramapo College Investigative Genetic Genealogy Center has solved dozens of cold cases in the last few years by using DNA technology, and they recently added the case of John Thiellesen to their list.

Thiellesen was found alive and unconscious on the sidewalk of Third Avenue and West Madison Street in Phoenix in August 2004.

Phoenix Emergency Medical Services took him to St. Joseph’s Hospital. He was pronounced dead on Aug. 17, 2004.

Remained Unknown

For more than 20 years, his identity remained unknown. The Phoenix Police Department used fingerprints and entered DNA evidence into the Combined DNA Index System (CODIS), but didn't get answers.

Then, last September, the Maricopa County Medical Examiner's Office contacted the Ramapo College Investigative Genetic Genealogy Center, located in Mahwah.

Investigators sent a portion of a bloodstain to Genologue in Tucker, Ga., where a DNA extraction and whole genome sequencing was performed, said the IGG Center staff. In October of 2024, Genologue sent files to Parabon Nanolabs in Virginia for bioinformatics.

In November of 2024, the genotype files were received by the IGG Center and uploaded to GEDmatch Pro and FamilyTreeDNA to try and identify the "John Doe."

Undergraduate students in the IGG Workshop course at Ramapo College began working on the case, but were unable to identify him before the semester ended in late 2024. So staff took over.

Third Cousins Found

Before winter break, the IGG staff found two of the man's third cousins.

They suggested John Thiellesen as a candidate to investigator Christen Eggers at the Maricopa County Medical Examiner's office.

Investigators got a DNA sample from one of Thiellesen's siblings.

In fact, Thiellesen's family had never forgotten about him.

Searched For Years

He was listed on social media as "Still Missing" in a post by the Toledo, Ohio police department in September of 2023.

The post reads, "On 9/1/2004, 42-year-old John Thiellesen was reported missing by his brother. John suffered from mental health issues and called his sister, stating that he had 'cleansed himself' and was planning on jumping into the Maumee."

The Maumee River is located in Ohio, around 2,000 miles from where Thiellesen was found.

"John is a white male. At the time of his disappearance, he was 6’0 and 110 lbs with black hair and hazel eyes. The picture of him is from approximately 2004," says the post.

It was just last month that Maricopa County investigators positively confirmed Thiellesen’s identity.

“I have had the honor of working with Ramapo College for the past couple of years and our collaborative efforts have led to not only this identification but many others in progress," said Eggers. "Ramapo College has become a beacon of hope for individuals and families across the nation."

“This case showcases the power of investigative genetic genealogy to close longstanding missing persons cases,” said Cairenn Binder, assistant director of the IGG Center. “Every John and Jane Doe is the answer to a family missing a loved one."

“I’m proud of the work our Cold Case Unit is doing to bring answers and closure to the family members of missing and murdered Arizonans,” said Arizona Attorney General Kris Mayes.

Nationwide, the IGG Center has helped solve 28 cases and has 39 active cases. To learn more about the IGG Center’s work, visit ramapo.edu/IGG. You can also read these related stories on Patch about the cases:

Other Cases Solved By The IGG

• Missing Mom Walked Away From Pennsylvania Home. Now Her Kids Have Answers.
• Female Artist, A Hitchhiker, Was Killed 50 Years Ago. NJ Students Cracked The Case.
• Jawbone In Boy's Rock Collection ID's As That Of Dead Marine By NJ Students