And, despite the best efforts of law enforcement officials, more than 6,000 more unsolved murders and abductions are added to that number every year.
While the advantages of DNA advancements are increasingly giving closure to families of cold case victims, some dating back for decades, a significant number of those crimes—40 percent—remain unsolved, based on the FBI report.
Research into old murder cases—as well as current cases—also can reveal where investigators may have missed some of the critical details that could have led to an arrest and a conviction.
Here are five ways that details that could go have gone missing in an investigation that eventually went cold:
Focusing only on what you expect to find at a crime scene
The brain wants to draw conclusions when coming up on the scene of a crime. It’s human nature. But it’s critical for law enforcement officials to resist the temptation to identify a certain type of weapon or focus only on one area of a room.
That’s how important details can go missing. As a detective, if you’re looking for specific evidence based on what you assume, there’s a risk of overseeing other critical evidence.
By observing a crime scene objectively and thoroughly from all angles — without an expectation of what they will find, experienced law enforcement officials will be able to hone in on important details.
Immediately focusing on one suspect or profile type early in the case
Many murderers have been able to commit gruesome crimes — and keep on doing it on their way to become a serial killer because, in some cases, law enforcement officials had too quickly nabbed the wrong person — or developed the wrong profile.
That was the case with the Golden State Killer, who went undetected for four decades until DNA technology resulted in his recent arrest.
Although investigators didn’t have the advantage of that technology then, they did miss some opportunities. In one case, law enforcement officials failed to connect the killing of a Santa Barbara County, Calif., couple, Lyman and Charlene Smith, to the serial killings because they already had a profile in mind. The victims were tied with a cord, similar to other Golden State Killer victims, but detectives assumed the Smith killer was someone that knew the couple because the attack was up close and brutal — like a crime of passion.
They eventually arrested Lyman Smith’s business partner, but he was freed because of lack of evidence.
By focusing on one type of criminal, investigators run the risk of missing details that could lead them to the real killer.
Failure to protect the crime scene
A murder investigation can be a magnet for human error as police officers, technicians, crime scene investigators and gawkers arrive at the crime scene.
And evidence — from footprints, hair fragments and fingerprints to blood spatter and broken glass — can be incredibly fragile. One wrong inadvertent move can easily contaminate the evidence — making it useless in a crime case.
Detectives assigned to the case must take extra care to ensure that the integrity of the crime scene remains intact.
Falling short on quality photographs, videos and sketches
A team of investigators only have a small window to capture a comprehensive image/story that answers the Who, What, When, Where and Why questions of a crime scene.
The evidence gathered can only do so much. Images and sketches are powerful in recreating the story of the crime in the minds of jurors and judges in a courtroom. They can back up the evidence and, as a result, the prosecutor’s case.
In some cases, images also can reveal patterns and details that could have gone missing during the initial in-person assessment of the crime scene.
Investigators who fail to capture the scene in a comprehensive array of photographs, videos and sketches could set themselves up for missing critical details that could have shed light in the case.
Failing to connect the dots between other crime scenes
The crime scene where the body is found isn’t necessarily the only place where crimes leading up to it were committed.
Investigators may fail to quickly identify the possibility that a body was dumped at the current crime scene location. As a result, other secondary crime scenes could go missing for hours, perhaps even days, which could lead to critical evidence being disturbed or completely washed out by other factors, including weather.
When investigating a crime, investigators should immediately start thinking about how the perpetrator entered and exited the crime scene area. Stairwells, alleys, roads, woods and other areas should not be ruled out. Otherwise, critical evidence can be entirely missed.
Closing cold cases—the possibility is greater with the right details
With more and more investigators exploring the possibility of closing cold cases, the success of their outcomes could largely depend upon how previous investigators captured all of the right details.
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