His name was Robert Clayton French, but how did he die?
It took 15 years, but skeletal remains found near the Troutdale Airport in May 1996 finally have a name - Robert Clayton French.
Now, volunteer Cold Case detectives hope anyone with information about the man will provide the nugget of information needed to solve the mystery of his death.
A man walking his dog in a grassy field east of the airport by the old Reynolds Aluminum plant discovered the remains when his dog retrieved a bone and then found a skull on May 15, 1996, said Detective Jim McNelly.
Explorer Scouts, on their hands and knees, searched three to four acres finding nearly every bone except those of the hands and feet.
McNelly, then the lead detective on the case, worked the scene with Nici Vance, who was on her first case as a new hire with the Oregon State Police as a forensic anthropologist.
They noted the remains appeared to have been exposed to the elements for at least a year. They were those of a middle-aged man, about 5 feet 5 inches tall with extensive dental work. His left lower arm bones had been broken and surgically held together with two steel plates. His jeans and shirt were tattered, but they made out the words 'Walla Walla College' on the shirt.
But the promising leads led nowhere. Instead of being a serial number as they hoped, the digits on the steel plate were a lot number, and 30,000 plates were manufactured in that lot, Vance recalled.
With no way to establish how he died or who he was, McNelly and Vance shelved the case. Ten years later, when the Oregon State Police crime lab moved to new offices in Clackamas, 53 sets of unidentified skeletal remains, including those found in the Troutdale field, also made the move.
Vance, who is now the state forensic pathologist for the Oregon State Medical Examiner's Office, set about creating an inventory of the remains. She reorganized them, improved storage and began the time-consuming task of trying to find names to go with the bones.
'These are not just boxes of evidence,' she said. 'These are people with loved ones who need answers.'
One by one, she examined each case, searching for a suitable bone to send to a federally funded laboratory at the University of North Texas. The university analyzes DNA, then compares its findings with national law enforcement, medical examiners and missing person databases.
In late 2009, Vance sent three bones from the Troutdale field - two lumbar vertebras and a right rib - to the university for testing. His DNA matched that of a man with a felony drug conviction in 1995, a conviction that required him to submit an oral swab for the DNA databank.
That man was Robert Clayton French.
Multnomah County's Cold Case volunteers contacted French's brother, Richard, in Michigan. And while a fuller picture of the man's life emerged, his cause of death remains a mystery.
Born March 18, 1944, in Florida, he grew up in Tecumseh near Ann Arbor, Mich. He was a teacher in Michigan and Canada, studied Jungian psychology in Switzerland and earned a doctorate in counseling at Idaho State University.
In 1995, he moved to Portland, telling family he wanted to visit a friend he'd met while in Switzerland. His brother last saw him in February 1995 before he moved to Portland.
He never heard from him again. Richard hired detectives and private investigators to find him, but struck out. In 2001, Richard filed a missing person's report with the Portland Police Bureau and had him declared legally dead in 2004.
While in Portland, French lived the life of a transient. Police arrested him several times for drug offenses, as well as violent offenses. He also had Crohn's disease and bi-polar disorder, which he refused to medicate.
'He could be combative, argumentative, arrogant, in people's faces,' McNelly said. 'He presented the kind of personality that could evoke a violent response from somebody.'
The case is now considered active, but McNelly is not calling the death suspicious. At this point, it's undetermined. The Crohn's disease could have caught up with him, or his mental illness, or his drug abuse, or his transient lifestyle.
'It's just a mystery,' McNelly said. 'But we owe it to the family to try to find out. We'd sure like to know anyone who had any contact with him, good or bad.'
Vance is fascinated and saddened by the man's story.
'It's sad but compelling,' she said, adding that despite such detail about his life, detectives are no closer to finding out how he died.
Meanwhile, she will keep submitting bones from skeletal remains for DNA testing. Since 2007, 12 of the 53 sets of skeletal remains preserved in the state crime lab have been identified.
Her goal is to identify everyone.
'This is my calling now,' she said.