Cross-examination will Go in Raw, Wreck Your Credibility, and Leave You Begging for a Safe Word

TL:DR

“Opinions are like assholes; everyone has one, and they all stink.” – One of my Bootcamp Drill Instructors

Expect your credibility to be attacked in court. Opposing counsel isn’t just looking to poke holes in your findings but to obliterate your opinion. They could care less if you get fired and can never work in DF/IR again as long as it means your testimony is discarded in their case.

You better be prepared before taking the oath.

The details

Early in my career, I walked right into a trap. An attorney asked if I trusted a specific forensic tool to be right all the time—I made the mistake to agree even though I didn’t. It felt like that Tom Cruise “A Few Good Men” court scene of being rushed, pressured, and forced to give a one word answer.

The second I said it, I regretted it. It was too late to fix it and I tried; I had handed the opposing attorney exactly what he wanted to attack the tool instead of my analysis. That mistake stuck with me. I will never let it happen again. It was only because my work was correct that the case wasn’t harmed.

I’ve seen other examiners make similar mistakes of overstating the accuracy of a tool, trusting an automated report without verification, or assuming that a parsed artifact means exactly what it appears to mean. This is how experts get their ass handed to them.

Few forensic examiners stop to think about the real consequences of their work: Your findings can determine whether someone spends the rest of their life in prison or walks free.

• Screw up, and the guilty walk.
• Screw up, and the innocent go to prison.

This job is not about looking smart or collecting a paycheck. It’s about getting it right every single time because the cost of getting it wrong is too high. There is no room for error. This is a zero-sum game.  There are no second chances. You must be right all the time.

The Risk of Doing Exactly What You Were Told

The fastest way to fail as a forensic examiner is only to do what you were told without guiding the legal team that more needs to be done. If you are asked/paid to do one thing and are expected to testify only to that giving an expert opinion, inform your attorney about the pitfalls of your testimony based on limited information. Opinions are not “expert opinions” based on limited information.

Imagine being allowed only to see half a football field for the Superbowl. Then asked for an “expert opinion” of how the game went. That is the same thing when given partial evidence or excluded from looking at evidence that can either prove or disprove your work and opinions.

If your approach to an investigation is to follow instructions without question, you are not an investigator—you’re a button pusher. Button pushers miss context, make assumptions based on limited information, and don’t apply critical thinking to not only the specific artifacts but how each artifact and every artifact fits in the bigger picture.

Before you hand over your findings, ask yourself:

• Did I look at everything that could be relevant?
• Did I verify tool output against raw data?
• Did I analyze the full context, or just what I was asked to?
• What is the worst that can happen if I am wrong (to the case, my career, the victim, the suspect, and the field)?

Bias Will Destroy Your Credibility

Every examiner has bias, whether they admit it or not. Actually, those who deny having any bias are the worst offenders for letting their bias influence their opinions.

I’ve seen it where examiners shape their analysis to fit what their client wants, sometimes unknowingly, sometimes deliberately. Either way, it’s a fatal mistake. As a special master on multiple cases, I’ve experienced the unmistakable difference between true impartiality and the subtle pull of working for one side. There’s no comparison when neutrality is absolute; ask anyone who has been a special master. They will tell you that there is a huge difference in how you see the case as a court-appointed special master having the only duty being directly to the court and not to either party.

The Dartboard Analogy: Why Methodology Matters

Digital forensics is like throwing darts at a board.

Like an experienced forensic examiner, a skilled player has a repeatable, precise technique and can consistently hit the target. A first-time player is like an untrained examiner and might hit the bullseye occasionally, but without skill or methodology, they can’t do it consistently.

Forensic opinions work the same way. If your methodology isn’t consistent, repeatable, and defensible, your findings are nothing more than a lucky shot, which is like red meat for a lion in the courtroom.

Your Opinion Is Tested in Every Room, Not Just the Courtroom

Even if you never set foot in court, your forensic opinion is scrutinized every time you present your findings.

• In the boardroom, executives will challenge you: “How do you know?”
• In the conference room, clients will push back: “Are you sure?”
• In your boss’s office, leadership will demand: “Can we act on this?”

Forensics is more than just finding evidence, it’s about defending your conclusions. If your findings guide legal decisions, policy changes, or high-stakes corporate actions, your opinion must be just as rock-solid as testifying in court.

One flawed conclusion can mean lost cases, wrongful arrests, bad terminations, or massive security failures. There is no excuse for sloppy work.

Grow Some Gonads: Speak the Hard Truths

If you’re afraid to tell the truth, you don’t belong in DF/IR. This job isn’t about pleasing clients: It’s about getting it right, no matter how inconvenient.

Weak examiners soften conclusions, hedge findings, or avoid confrontation. That’s cowardice. Your credibility is worth more than anyone’s approval. It takes guts to say, “The evidence doesn’t support that,” or “You’re wrong.” It takes integrity to admit, “I don’t know,” instead of bluffing.

It’s ok if you don’t like this requirement or don’t want to be harshly honest when needed. You just need a different career because you are a liability in DF/IR.

Laws, SOPs, Guidelines, Rules: When to Step Outside Them

All of us operate within Standard Operating Procedures (SOPs), guidelines, regulations, best practices, and legal frameworks that define how we conduct DF/IR investigations. These exist to maintain consistency and integrity in forensic work.

But what happens when the case doesn’t fit the framework?

1. The Hard Limits/Foundations of DFIR

Some things are just not possible, no matter how good you are (If logs were never created, you can’t recover what was never there).

No tool, method, or skillset will change physical reality. You can’t go outside this boundary even if you tried.

2. When SOPs Don’t Cover the Situation

Sometimes, you must step outside of an SOP because the case demands it. (What if the standard tool doesn’t support the data source?).

If you must go beyond the SOP, you better:

• Clearly articulate the why and how.
• Document the methodology you created.
• Ensure your method is repeatable and defensible.
• Be prepared to explain and defend your choices under scrutiny.

If you break from the framework without justification, you’ve just given opposing counsel everything they need to discredit your entire case.

But sometimes, you may have to venture outside the rules or best practices. Most of these things (SOPs, best practices, etc..) are “advice.” The totality of a circumstance may require you to go outside of what is commonly accepted. This applies to laws as well!  In exigent circumstances, even the warrant requirement can be bypassed. Articulable reasoning is required every single time.

And yes, if you color outside the DF/IR lines, you will be called on the carpet to defend your actions. If you were right, cool. If not, stand by…

If you disagree with this, explain to me why we are not still pulling the plug from the back of every computer and creating a full disk image of every storage device? Or why we are not seizing every piece of hardware for evidence, to include the monitors and keyboard?  The answer is that best practices, SOPs, and rules must constantly change to fit the constant changes in the world of technology.

Your role in evidence being admitted in court

Examiner: “I believe this is evidence.”

Attorney: “I submit this as evidence.”

Judge: “This evidence is admissible (or inadmissible).”

Jury: “This evidence is credible (or not credible).”

Be sure that your collection, analysis, and interpretation of evidence is able to pass through these gates before it is even submitted as evidence. Explain the “why” and be “credible” when articulating your findings.

Expert opinions take on a higher level of difficulty for testimony acceptability. They are based on facts, forensic methodology, scientific principles, cross-validation, experience, technical knowledge, contextual analysis, awareness of tool limitations, legal standards, and absolute neutrality. The more you have, the more ‘credible’ you will be and able to be court qualified as an expert.

On top of that, your opinion can be influenced by any number of biases, stress, lack of focus, or outside pressures. When these come out, your opinion carries little to no weight.

Final Takeaways: The Standard Is Higher Than You Think

1. Methodology is non-negotiable. If you don’t have a structured, repeatable process, your opinion is worthless. You are blindly throwing darts.

2. Bias will creep in; check yourself. If your opinion changes based on who hired you, you’re not an expert. You’re something that I won’t state here.

3. If the SOP doesn’t cover it, you better have a rock-solid justification for why you went outside it.

4. Forensic tools don’t think; you do. Verify everything.

This job has no room for excuses, shortcuts, or sloppy work. Get it right. Every time. Or find a new job.

Thanks to Craig Bowling (https://x.com/Craig__Bowling/status/1885772256753901910) and a few other social media posts (https://x.com/Brett_Shavers/status/1885729341184888999) on expert opinions for inspiration for this blog post.

Disclaimer: I’m not a lawyer, but I once met one…