Criminal Attorneys Aren't Just for Criminals

How Does Evidence Get Into A Criminal Case?

by Eva Holmes

If a case is headed for trial under criminal law, one of the central issues is whether the prosecution will or won't be able to use certain pieces of evidence. A criminal law attorney will make an effort to keep the worst evidence from showing up at trial. If you're wondering how that might work in a case, here's how these things tend to go.


Once it becomes clear that a case is heading to trial, the judge will order discovery. This is a legal process that ensures that no one is blind-sided at trial.

Any evidence either side intends to use has to be disclosed during the discovery process. This allows the opposite side a fair chance to learn what the alleged evidence is and to raise any questions about its value. If there are concerns about the veracity of the evidence, a lawyer can raise those to the judge long before a jury would see it. That allows the judge to bar any questionable evidence from going before the jury.

There are a few scenarios where prosecutors might introduce evidence once a trial is rolling. However, a judge will likely hold a separate hearing regarding the evidence. Likewise, they will raise lots of questions about why it is just appearing. Similarly, the defense will still have the right to examine the evidence and raise questions. The judge can still bar the evidence if they feel it's inappropriate, not significant, or simply too late to the case.


The majority of issues involving evidence should be resolved during pre-trial hearings. After reviewing evidence from discovery, a criminal attorney may file a motion. This is a request that the judge will review their concerns and address them in court.

Suppose a lawyer had questions about how the police handled a blood sample in a DUI case involving allegations of drug use. The attorney could ask the court to consider who handled the sample and whether they can prove that an outside party might have tampered with it. The court might then order the police officers and lab technicians who handled the sample to explain how they secured it every step of the way. If there was a problem, the judge might bar the evidence from trial.

A court may also look at broader legal questions about evidence within criminal law. For example, was the evidence obtained before a police officer had established probable cause for a search? Once more, a judge can bar the evidence if it is problematic.