It can be frustrating when the police withhold details about a crime, especially one that has remained unsolved for a significant length of time.
We are curious creatures. We want to know who did it, why they did it, and how it all unfolded.
Unfortunately, there are a number of reasons why releasing evidence to the public can irreversibly damage an ongoing investigation.
Withholding evidence can protect the investigation against false confessions.
The most obvious reason to withhold evidence is to protect the investigation against false confessions.
In the past, people have confessed to crimes that they didn’t commit. Some were mentally ill, while others simply “snapped” due to the pressure of being interrogated.
There have also been examples of people incriminating themselves to protect loved ones.
By withholding key details, the police can figure out if someone is being honest or not. If the person’s account of the crime doesn’t line up with evidence that has been withheld from the public, then the investigators will quickly realize that they are lying.
Fake witnesses exist.
Unfortunately, there are a small minority of people out there who like to insert themselves into big cases—especially ones that receive a lot of media coverage.
These attention-seekers will lie and claim that they witnessed something that never happened.
They might say that they interacted with the victim or that the main suspect in the case attempted to harm them.
For example, over the years, dozens of women have claimed that they narrowly survived an encounter with serial killer Ted Bundy. However, many of these claims weren’t made until after he was convicted and the details of his crimes came to light.
Sadly, some people will lie to feel important, regardless of what damage their dishonesty might cause.
When these types of people come forward to “help”, investigators can sometimes weed them out by comparing their claims against the evidence.
People are often unreliable witnesses.
Honest witnesses can also be unreliable, as people will often recall conflicting details about the exact same event.
Simply put, our memories aren’t as accurate as we like to think they are.
Despite this, certain people have an unshakeable and stubborn belief in their own recollection of events. They can also become highly defensive if you even raise the possibility that they might have been mistaken.
For example, you or I might say, “I think that I saw Joe Bloggs’ car”, whereas they will confidently state, “I swear, I definitely saw Joe Bloggs’ car!”
Again, withholding evidence can be a powerful tool to deal with these kinds of witnesses.
If they are “certain” that they saw the victim somewhere, but phone records and surveillance footage contradict their sighting, then the police will write their statement down, thank them for coming forward, and never contact them again.
Of course, these are the same people who often appear in the media at a later date, claiming that the police gave them the cold shoulder. And of course, the media will give them a platform simply because they don’t have access to the evidence that proves they were mistaken.
Releasing evidence can influence the offender’s behavior.
Releasing too much evidence can influence the offender’s behavior and jeopardize an ongoing case.
For example, a key piece of evidence might provide a hint about his identity or how he committed the crime.
In this case, it is better to keep your cards close to your chest.
If he learns that investigators are honing in on a certain area or aspect of his crime, then there is a good possibility that he will destroy key evidence that he previously thought was safe.
If the way in which he operates provides a vital clue about his background, then he may purposely modify his behavior to mislead the police.
People often forget that the offender will usually pay close attention to media coverage of their crimes. When the police release a piece of evidence to the public, they are also releasing it to him.