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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 (MP42480) and 3 other sources
Jon Jeffrey Challberg, 38, was last seen on February 6, 1986, in Sacramento, California. On that evening, he attempted to swim across the Sacramento River, but he never made it to the other side and has not been heard from since. Despite efforts to locate him, no further information has emerged, leaving his case unresolved for decades.

Challberg was described as a white male, around 5'11" to 6'0" tall. At the time of his disappearance, few details beyond the attempted swim and subsequent disappearance were available. His case remains classified as a missing person, with law enforcement agencies continuing to seek any information that might help solve the mystery of his disappearance.
Last Seen: Feb 6, 1986

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.

82%Moderate
John Doe — Sacramento, California
UP2399 • Found Feb 20, 1986
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Sex ✓Male
Age 85%Est. 30–50 vs 38
Race 100%White
Location 100%3 mi away, same county
TimingFound 14 days after last seen
Height 100%6'1" vs 5'11"–6'0"
Weight 100%210 lb vs 190–200 lb
Hair 50%Brown vs Blond
80%Moderate
John Doe — Sausalito, California
UP17718 • Found Sep 9, 1990
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Sex ✓Male
Age 100%Est. 35–45 vs 38 when missing
Race 100%White
Location 82%74 mi away, same state
TimingFound 5 years after last seen
Height 100%5'11" vs 5'11"–6'0"
Weight 89%160 lb vs 190–200 lb
Hair 50%Brown vs Blond
Eyes 70%Gray vs Blue
79%Possible
John Doe — Sausalito, California
UP17743 • Found Feb 17, 1987
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Sex ✓Male
Age 100%Est. 33–39 vs 38 when missing
Race 100%White
Location 82%74 mi away, same state
TimingFound 12 months after last seen
Height 100%5'10" vs 5'11"–6'0"
Weight 89%160 lb vs 190–200 lb
Hair 10%Black vs Blond
78%Possible
John Doe — Oakland, California
UP54081 • Found Dec 12, 1986
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Sex ✓Male
Age 100%Est. 25–40 vs 38
Race 100%White
Location 84%70 mi away, same state
TimingFound 10 months after last seen
Height 84%5'9" vs 5'11"–6'0"
Weight 100%219 lb vs 190–200 lb
Hair 50%Brown vs Blond
Eyes 0%Brown vs Blue
78%Possible
John Doe — California - unidentified case UP2363
John Doe — California
UP2363 • Found Mar 9, 2003
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Sex ✓Male
Age 100%Est. 30–45 vs 38 when missing
Race 100%White
Location 99%13 mi away, same county
TimingFound 17 years after last seen
Height 100%5'11" vs 5'11"–6'0"
Hair 50%Brown vs Blond
78%Possible
John Doe — San Francisco, California
UP5919 • Found Apr 1, 1987
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Sex ✓Male
Age 85%Est. 40–60 vs 38 when missing
Race 100%White
Location 82%76 mi away, same state
TimingFound 14 months after last seen
Height 100%5'10" vs 5'11"–6'0"
Weight 100%190 lb vs 190–200 lb
77%Possible
John Doe — San Francisco, California
UP5927 • Found Oct 2, 1989
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Sex ✓Male
Age 85%Est. 30–50 vs 38 when missing
Race 100%White
Location 82%76 mi away, same state
TimingFound 4 years after last seen
Height 100%6'0" vs 5'11"–6'0"
Weight 100%205 lb vs 190–200 lb
Hair 50%Brown vs Blond
77%Possible
John Doe — San Francisco, California
UP5923 • Found Oct 17, 1987
View case
Sex ✓Male
Age 85%Est. 30–50 vs 38 when missing
Race 100%White
Location 82%76 mi away, same state
TimingFound 20 months after last seen
Height 100%5'11" vs 5'11"–6'0"
Weight 68%140 lb vs 190–200 lb
Hair 40%Gray vs Blond
76%Possible
John Doe — Napa, California
UP69733 • Found Dec 14, 2007
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Sex ✓Male
Age 100%Est. 28–42 vs 38 when missing
Race 100%White
Location 90%47 mi away, same state
TimingFound 22 years after last seen
Height 100%6'0"–6'3" vs 5'11"–6'0"
76%Possible
John Doe — Forestville, California
UP93104 • Found Dec 31, 1994
View case
Sex ✓Male
Age 100%Est. 35–45 vs 38 when missing
Race 100%White
Location 82%75 mi away, same state
TimingFound 9 years after last seen
Height 100%5'11"–6'1" vs 5'11"–6'0"

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.