Crime Solvers Central
Crime Solvers Central
302 Cases Solved. Advancing justice for missing persons, unsolved homicides, unidentified and unclaimed remains.

Case Description

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Summary based on the NamUs case record (MP38625) and 3 other sources
Mark Thomas Schley, a 29-year-old man, was last seen on December 17, 1984, in Jacksonville Beach, Florida. On that day, Schley left town with a friend and has never been heard from again. His friend, who has since passed away, became the primary suspect in Schley's disappearance, but no conclusive evidence has surfaced. Schley did not return from the trip, and there have been no significant developments in his case over the years.

Schley is described as being 5'10" tall, weighing 140 pounds, with brown hair and blue eyes. He also had a scar on his groin and may have used the last name "Welby." The case has remained unsolved, with no substantial leads emerging since the time of his disappearance. Law enforcement continues to classify it as a missing person case, but foul play has not been ruled out.

Authorities encourage anyone with information regarding his case to contact the Jacksonville Beach Police Department, as his disappearance remains one of the unsolved cases from the 1980s in Florida. Despite the time that has passed, there is still hope that new information may come to light.

Last Seen: Dec 17, 1984

Possible Unidentified Matches (10)

Unidentified remains cases whose details are consistent with this person, ranked by how closely they compare. Fields that are unknown in either case are left out of the score.

80%Moderate
John Doe — Jacksonville, Florida - unidentified case UP1127
John Doe — Jacksonville, Florida
UP1127 • Found Nov 18, 1994
View case
Sex ✓Male
Age 100%Est. 21–35 vs 29 when missing
Race 100%White
Location 100%9 mi away, same county
TimingFound 10 years after last seen
Height 52%5'6" vs 5'10"
Weight 100%149 lb vs 140 lb
Hair 100%Brown vs Brown
Eyes 100%Blue vs Blue
79%Possible
John Doe — Jacksonville, Florida - unidentified case UP747
John Doe — Jacksonville, Florida
UP747 • Found Aug 28, 1998
View case
Sex ✓Male
Age 100%Est. 30–45 vs 29 when missing
Race 100%White
Location 100%Same area, same county
TimingFound 14 years after last seen
Height 100%5'10" vs 5'10"
78%Possible
John Doe — Baldwin, Florida - unidentified case UP748
John Doe — Baldwin, Florida
UP748 • Found Sep 23, 1996
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Sex ✓Male
Age 100%Est. 33–42 vs 29 when missing
Race 100%White
Location 94%34 mi away, same county
TimingFound 12 years after last seen
Height 100%5'9" vs 5'10"
78%Possible
John Doe — Silver Springs, Florida - unidentified case UP6052
John Doe — Silver Springs, Florida
UP6052 • Found Dec 29, 1992
View case
Sex ✓Male
Age 100%Est. 17–30 vs 29 when missing
Race 100%White
Location 80%83 mi away, same state
TimingFound 8 years after last seen
Height 100%5'11" vs 5'10"
Weight 91%160 lb vs 140 lb
77%Possible
John Doe — Georgia - unidentified case UP4700
John Doe — Georgia
UP4700 • Found Oct 29, 1987
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Sex ✓Male
Age 100%Est. 19–29 vs 29 when missing
Race 100%White
Location 69%130 mi away
TimingFound 3 years after last seen
Height 100%5'9" vs 5'10"
Weight 96%157 lb vs 140 lb
76%Possible
John Doe — Georgia
UP17604 • Found Mar 16, 1988
View case
Sex ✓Male
Age 100%Est. 20–30 vs 29 when missing
Race 100%White
Location 71%120 mi away
TimingFound 3 years after last seen
Height 100%5'10" vs 5'10"
Hair 100%Brown vs Brown
Eyes 0%Brown vs Blue
76%Possible
John Doe — Jacksonville, Florida - unidentified case UP804
John Doe — Jacksonville, Florida
UP804 • Found Jun 22, 1987
View case
Sex ✓Male
Age 41%Est. 40–60 vs 29 when missing
Race 100%White
Location 99%15 mi away, same county
TimingFound 3 years after last seen
Height 100%5'11" vs 5'10"
Weight 99%155 lb vs 140 lb
Hair 100%Brown vs Brown
75%Possible
John Doe — Miami, Florida
UP16420 • Found Nov 20, 1984
View case
Sex ✓Male
Age 100%Est. 20–30 vs 29
Race 100%White
Location 43%321 mi away, same state
TimingFound same day as last seen
Height 100%5'9" vs 5'10"
Weight 100%145 lb vs 140 lb
Hair 100%Brown vs Brown
75%Possible
John Doe — Jacksonville, Florida - unidentified case UP13256
John Doe — Jacksonville, Florida
UP13256 • Found Aug 21, 2011
View case
Sex ✓Male
Age 85%Est. 48–70 vs 29 when missing
Race 100%White
Location 100%12 mi away, same county
TimingFound 27 years after last seen
Height 100%5'9" vs 5'10"
75%Possible
John Doe — Fernandina Beach, Florida - unidentified case UP850
John Doe — Fernandina Beach, Florida
UP850 • Found Oct 9, 1989
View case
Sex ✓Male
Age 100%Est. 20–30 vs 29 when missing
Race 100%White
Location 95%27 mi away, same state
TimingFound 5 years after last seen
Hair 50%Red vs Brown

These comparisons are generated automatically from public NamUs case data and are not confirmed identifications. Only DNA, dental or fingerprint comparison by investigators can confirm an identity. If you believe two cases are connected, contact the agency handling the unidentified case.

Unidentified photos are blurred because many are post-mortem. Tap a photo to reveal it.