With each passing year, America's criminal law system leans more and more on technology to provide evidence. From breathalyzers to shot spotters, there are a lot of machines backing prosecutorial claims.

Consequently, a criminal law attorney has to think more than ever before about how to respond when prosecutors say some gadget proves their client committed an offense. If the case against you appears to hinge on some piece of technology, here are four ways to address the problem.


Foremost, a criminal law attorney wants to know what kind of technology is so reliable as to deserve to count as evidence. On the upside for defendants, American courts have been addressing the role of technology in cases going back to the introduction of fingerprinting in the 1800s.

A judge will order the prosecution to provide all identifying information about the technologies in question. This goes well beyond the make and model of the device. You will also be able to discover the serial numbers for the equipment, maintenance logs, and even who had access to the systems.


Lawyers will want to research both the general histories of systems and the specific problems of particular units. Also, they'll want to examine how police and prosecutorial handling of the systems does or doesn't match with accepted practices.

Equipment recalls and reports are usually the starting point. A criminal law attorney will want to see if there is a pattern of problems. For example, a particular radar gun might be especially hard to calibrate. If the core of a reckless driving case was the claim the radar gun had registered an especially high number, a lawyer would likely attack that problem in court.

Motion to Suppress

In most cases, the go-to approach will be for your attorney to move that the court will suppress the evidence. Your lawyer will tell the court what they've learned in their research. The prosecution will have a chance to explain why the evidence is okay. If the judge is concerned after hearing the two sides' views, they can exclude the evidence.

Even if the motion is unsuccessful, it may lay the groundwork for an appeal. For this reason, a criminal law attorney will at least want to get their objections on the record.

Frye Motion

In a Frye Motion, the defense asks the court to exclude the evidence because it's not widely scientifically accepted. The goal is still suppression, but the defense rejects the idea the technology provides viable evidence. In a case from Rochester, NY, for example, the judge excluded evidence from shot-tracking technology for this reason among others.