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Crime Solvers Central
298 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 (MP22714) and 4 other sources
On a spring afternoon in 1986, Dennis M. Diamond and a friend, Donald Peterson, left Diamond's home in Franklin Township, New Jersey. Diamond, a 34-year-old house builder, told his wife to start dinner, mentioning they would be back in about an hour and a half. The two men were reportedly heading to Philadelphia in Diamond's black 1984 Buick Regal. This would be the last time their families would see them. When neither man returned home, they were reported missing on April 25, 1986. Dennis, who was a father to four young children, left behind all of his personal belongings, including his eyeglasses which he needed for night vision.

The investigation into the disappearance of Dennis Diamond and Donald Peterson took a turn when police uncovered a meth lab in a converted chicken coop on the property where both men lived; Diamond was Peterson's landlord. Following this discovery, a warrant was issued for Peterson's arrest. The circumstances surrounding their disappearance grew more complex as time passed. Nearly two years later, on April 11, 1988, Dennis Diamond's Buick Regal was located in the parking lot of an Acme market in Upper Darby, Pennsylvania. The vehicle's identification number had been altered, and a member of the Warlocks motorcycle club had been seen driving it. When authorities attempted to question this individual, they found he had died of a drug overdose, adding another layer of mystery to the case.

Over the years, the search for answers has yielded few results. In 1997, a tip led investigators to search a private property in Woolwich Township with the belief that the men might be buried there, but the search was unsuccessful. Foul play is suspected in their disappearances. The case is characterized by a lack of significant leads and media attention since the initial investigation. At the time of his disappearance, Dennis Diamond was described as being 5'5' and weighing 183 pounds, with strawberry blonde hair and hazel eyes. He had a scar on his left arm. The disappearance of Dennis Diamond and Donald Peterson remains an unresolved case, leaving their families with unanswered questions about what happened on that April day in 1986.

Last Seen: Apr 19, 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.

83%Moderate
John Doe — Atlantic City, New Jersey
UP1685 • Found Aug 5, 1987
View case
Sex ✓Male
Age 100%Est. 30–40 vs 34 when missing
Race 100%White
Location 93%36 mi away, same state
TimingFound 16 months after last seen
Height 100%5'6" vs 5'5"
Weight 100%175 lb vs 183 lb
Hair 50%Red vs Blond
80%Moderate
John Doe — Newark, New Jersey
UP1439 • Found May 1, 1986
View case
Sex ✓Male
Age 100%Est. 30–40 vs 34
Race 100%White
Location 78%90 mi away, same state
TimingFound 12 days after last seen
Height 100%5'6" vs 5'5"
Weight 100%165 lb vs 183 lb
Hair 50%Brown vs Blond
79%Possible
John Doe — Philadelphia, Pennsylvania
UP53095 • Found Jun 21, 1994
View case
Sex ✓Male
Age 100%Est. 35–50 vs 34 when missing
Race 100%White
Location 95%27 mi away
TimingFound 8 years after last seen
Height 100%5'2"–5'4" vs 5'5"
Hair 50%Brown vs Blond
79%Possible
John Doe — Brooklyn, New York - unidentified case UP9079
John Doe — Brooklyn, New York
UP9079 • Found Aug 2, 1988
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Sex ✓Male
Age 100%Est. 25–40 vs 34 when missing
Race 100%White
Location 77%92 mi away
TimingFound 2 years after last seen
Height 100%5'6" vs 5'5"
Weight 73%140 lb vs 183 lb
Hair 50%Brown vs Blond
Eyes 60%Brown vs Hazel
79%Possible
John Doe — West Deptford, New Jersey - unidentified case UP1626
John Doe — West Deptford, New Jersey
UP1626 • Found Apr 26, 1986
View case
Sex ✓Male
Age 100%Est. 29–39 vs 34
Race 100%White
Location 98%18 mi away, same county
TimingFound 7 days after last seen
Height 36%5'10" vs 5'5"
Weight 100%195 lb vs 183 lb
Hair 50%Brown vs Blond
Eyes 60%Brown vs Hazel
79%Possible
John Doe — Philadelphia, Pennsylvania - unidentified case UP151698
John Doe — Philadelphia, Pennsylvania
UP151698 • Found Oct 13, 2025
View case
Sex ✓Male
Age 100%Est. 45–60 vs 34 when missing
Race 100%White
Location 96%26 mi away
TimingFound 39 years after last seen
Height 100%5'6"–5'8" vs 5'5"
Weight 89%150–155 lb vs 183 lb
Hair 50%Brown vs Blond
Eyes 100%Hazel vs Hazel
78%Possible
John Doe — Philadelphia, Pennsylvania
UP460 • Found Jul 14, 2006
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Sex ✓Male
Age 96%Est. 55–65 vs 34 when missing
Race 100%White
Location 96%26 mi away
TimingFound 20 years after last seen
Height 100%5'4" vs 5'5"
Weight 59%130 lb vs 183 lb
Hair 70%Gray vs Blond
Eyes 60%Brown vs Hazel
78%Possible
John Doe — Edison, New Jersey
UP1700 • Found May 21, 1996
View case
Sex ✓Male
Age 100%Est. 40–55 vs 34 when missing
Race 100%White
Location 83%71 mi away, same state
TimingFound 10 years after last seen
Height 100%5'6" vs 5'5"
Weight 100%170 lb vs 183 lb
78%Possible
John Doe — Philadephia, Pennsylvania
UP7463 • Found Oct 14, 1994
View case
Sex ✓Male
Age 100%Est. 35–45 vs 34 when missing
Race 100%White
Location 95%27 mi away
TimingFound 8 years after last seen
Height 52%5'9" vs 5'5"
Weight 100%181 lb vs 183 lb
Hair 50%Brown vs Blond
Eyes 100%Hazel vs Hazel
78%Possible
John Doe — New York, New York - unidentified case UP10330
John Doe — New York, New York
UP10330 • Found Oct 27, 1989
View case
Sex ✓Male
Age 100%Est. 30–45 vs 34 when missing
Race 100%White
Location 77%93 mi away
TimingFound 4 years after last seen
Height 100%5'5" vs 5'5"
Weight 51%125 lb vs 183 lb
Hair 50%Brown vs Blond
Eyes 100%Hazel vs Hazel

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.