Skip to main content
Please enter a legal issue and/or a location
Begin typing to search, use arrow keys to navigate, use enter to select

Scientific and Forensic Evidence

There are many types of evidence that are commonly used at trial, including items found at the crime scene and eyewitness testimony. Scientific and forensic evidence can be extremely helpful in proving your case, since they can often reveal otherwise hidden clues about the incident. However, there are rules and standards that these types of evidence must meet before they can be submitted during a trial.

The following provides an overview of scientific and forensic evidence as used in criminal trials.

What is Scientific Evidence?

You may be wondering what on earth scientific evidence could mean in regards to a trial. In general, scientific evidence is based off of knowledge that has been developed by using the scientific method. This means that the basis for the evidence has been hypothesized and tested and is generally accepted within the scientific community. This could mean that the theory on which the scientific evidence is based has been published in scientific journals and has been subjected to peer review within the scientific community.

Generally, many types of forensic evidence are often considered scientific evidence, like DNA matching, fingerprint identification, and hair/fiber evidence. The methods used to develop these types of evidence are generally beyond the scope of knowledge that judges and juries possess and are therefore normally introduced as scientific evidence.

When Scientific and Forensic Evidence May be Used

Although scientific evidence can strengthen a case, it may be excluded from a courtroom or trial in some instances. There are often many steps that must be taken before it can be put forth in a courtroom as factual evidence. In general, a scientific theory must have established itself in the scientific community and become generally accepted as the truth before it will be asserted as evidence at trial.

For example, because it has been around for so long and because it has proven to be reliable, evidence regarding fingerprint matching is generally admissible as forensic evidence in trial. In addition, things like radar and laser speed guns are generally accepted as being a valid method to tell the speed of a car at a given time and can be admitted as evidence. But keep in mind that there will often be new types of scientific evidence that parties will attempt to submit at trial -- science that may not have a solid foundation within the scientific community.

If one side of a trial wishes to submit scientific evidence that is not yet generally accepted within the scientific community, it often happens that the court orders a mini-trial to be held in order to determine the validity of the scientific theory on which the evidence is based. As an example, DNA evidence had to go through many mini-trials before it became generally accepted as valid evidence at trail.

In the future, we may see more mini-trials as more types of forensic evidence are introduced in court. As another example, many scientists are currently working on using functional Magnetic Resonance Imaging (fMRI) as a new type of lie detection machine (this works by imaging, in real time, the flow of blood around the brain). If, during a mini-trial, a judge can be convinced that a new, as-of-yet unproven, type of scientific evidence should be introduced at trial, then the judge will allow it to be presented.

A Criminal Defense Attorney Can Help Scrutinize the Evidence Against You

Believe it or not, there are ways to challenge scientific and forensic evidence, such as attacking the chain of custody of blood samples or the improper calibration of a radar gun. Many criminal defense attorneys specialize in scientific and forensic evidence and can call on expert witnesses in your defense. See what options are available to you by contacting a local defense attorney today.

Was this helpful?

Thank you. Your response has been sent.

You Don’t Have To Solve This on Your Own – Get a Lawyer’s Help

Meeting with a lawyer can help you understand your options and how to best protect your rights. Visit our attorney directory to find a lawyer near you who can help.

Or contact an attorney near you:

Next Steps

Contact a qualified criminal lawyer to make sure your rights are protected.

Begin typing to search, use arrow keys to navigate, use enter to select

Help Me Find a Do-It-Yourself Solution

Can I Solve This on My Own or Do I Need an Attorney?

  • Complex criminal defense situations usually require a lawyer
  • Defense attorneys can help protect your rights
  • A lawyer can seek to reduce or eliminate criminal penalties

Get tailored advice and ask your legal questions. Many attorneys offer free consultations.


 If you need an attorney, find one right now.

Copied to clipboard

Find a Lawyer

More Options