The Bias You Never See: How Forensic Objectivity Is Compromised Before You Even Begin

I’ve seen bias more times than I can count. Felt it breathing down my neck in courtrooms. I watched it silently eat through science like rust. And the worst part? Most of the time, I can’t stop it. I’m just watching. Watching while objectivity dies in silence.

Let me be blunt. A forensic investigator from the state police, let’s say an officer from the LKA or in the US, the FBI, testifying as a “neutral” expert witness? That’s a joke. She’s not neutral. She’s part of the prosecution. She will never lift a finger to exonerate the accused. She won’t do a damn thing if it might help the defense because neutrality isn’t rewarded. Obedience is.

I’ve seen experts who were too neutral lose all their court assignments. Not because they were wrong. Because they didn’t play the game. Because some judges want convictions. Let’s stop pretending they don’t exist.

There was this one case. A professor of human biology testified that a suspect, who appeared fully masked in a video, was identified with a probability of over 99.72%. You read that right. A masked figure. Identified. How? Because the professor knew that similar clothes had been bought via Amazon. That was enough for him to see through the mask. To “know.” That wasn’t science. That was allegiance.

What kind of bias was that? That was adversarial bias, maybe with a pinch of confirmation bias and a full spoon of overconfidence bias. Let’s call it what it is: conviction masquerading as expertise. I wrote a method-critical report about that case. Clean. Factual. But uncomfortable. And to this day, they still hate me for it at the regional court. Not because I was wrong. But because I didn’t bend. I didn’t stay quiet. I exposed the flaw. That’s what real forensics demands. Not loyalty. Courage.

Now, let’s break the rest of them down.

Contextual Bias. You hear the suspect has a record. Suddenly, even partial, smudged prints look like perfect matches. The lab doesn’t lie. But the mind behind the microscope does.

Expectation Bias. You’re told a DNA sample is supposed to match. So it does. Not because it really does. But because your brain needs it to.

Adversarial Bias. You get too close to the side that hired you. You stop analyzing and start defending. You’re not a scientist anymore. You’re a soldier.

Selection Bias. You highlight what helps. You ignore what doesn’t. No one tells you to. You just do.

Anchoring Bias. The first thing you hear sticks. Everything after that is filtered through it. Doesn’t matter if it’s true.

Hindsight Bias. Once you know how it ended, it all feels inevitable. Even if it wasn’t.

Overconfidence Bias. You’re so sure you’re right that you stop checking. You stop questioning. You stop thinking.

Availability Bias. Your past cases bleed into the current one. That one abuse case you can’t forget makes you see abuse where there may be none.

Allegiance Bias. You start echoing the views of the agency that always hires you. It’s not loyalty. It’s absorption.

Base Rate Neglect. You forget statistics. You treat common traits as rare. Furthermore, you make matches that aren’t unique sound like they are.

Blind Spot Bias. You believe you’re immune. That your experience protects you. That’s when you’re most vulnerable.

That’s where the forensic war is fought. Not in court. Not in labs. In the mind.

We don’t need just standards. We need introspection. We need to teach new experts that doubt isn’t a weakness. It’s protection. And we need the courts to understand that a clean lab coat doesn’t mean a clean mind.

I’ve testified, knowing full well the expert on the other side was wrong. Not lying. Just convinced. Too early. They stopped looking. Locked into a belief. And built everything on that foundation.

Forensics isn’t about being right. It’s about being honest. Brutally honest. With the evidence. With the process. With yourself.

And if you don’t see your own bias? It’s already taken control.

Our justice systems, no matter the country, are not flawless. And when those flaws go unchecked, innocent people get punished, and those with minor guilt sometimes face sentences far beyond what is fair. It is my duty to bring clarity into this process. To stand for transparency. And to call things exactly what they are. Expert witnesses must be 100% neutral. And I can say with certainty, based on everything I’ve seen, that most are not. But here’s the harder question: does the justice system even want that neutrality? Judges keep calling the same experts. Again and again. There are white lists. And black lists. And guess who ends up blacklisted? Those who swim against the current…