Minnesota DWI Defense Blog : Roseville DUI Defense Lawyer & Attorney : Ramsay Law Firm : Minneapolis, St. Paul, Minnesota

The Constitution’s Guarantee of Right to Trial by Jury

 Whenever a prosecutor charges a person with a crime that could result in jail, the Constitution provides that person with numerous constitutional rights. One of those sacred, longstanding rights is the right to a trial.  

 At its most basic, a trial is nothing more than a fact finding process. That means that everyone charged with a crime has the right to have a jury of his or her peers listen to the evidence and determine, based solely on that evidence, whether or not the State has proven that the “defendant” committed a crime beyond a reasonable doubt.

How Good Defense Lawyers Are Worth Their Value

Good Lawyers know how and what types of evidence can be presented to that jury.  Great lawyers know how to keep out evidence that should not be admitted at trial. 

Anyone who has watched Law and Order realizes that there are a variety of grounds for an attorney to get evidence suppressed. Usually, on TV, it’s because the evidence was obtained by police officers that broke the law.

However, in real life, it’s far more likely that an attorney will be attempting to suppress evidence because it’s simply not relevant, or because it is so unreliable that it would do nothing more than confuse the jury. Sometimes, it’s because the evidence looks good at first glance, but is really nothing more than smoke and mirrors. And this is where the phrase Frye-Mack comes into play. 

A Frye-Mack hearing is an evidentiary hearing, held before any trial takes place, and it is used to determine if “scientific evidence” can be presented against an accused defendant. It’s called a Frye-Mack hearing in Minnesota based upon two reported cases that outlined the procedure; United States v. Frye, a Washington D.C. case from the 1920's that dealt with a type of lie detector test, and State v. Mack, a Minnesota case from the 1980's that dealt with “hypnosis” testimony.

As a result of these two cases (and many others that followed), Minnesota has two very specific criteria that need to be met before the State can introduce scientific evidence to a jury. These criteria are aimed at preventing juries from being presented with “junk science.”

Frye-Mack Prong 1:  Has the test gained general acceptance in the scientific community?

Under what is called the “first prong” of Frye-Mack analysis, the State must prove that the scientific technique that is being used has gained general acceptance in the scientific community. As a fun example, we’ll use phrenology, or the belief that the personality traits of a person can be derived from the shape of that person’s skull.

 In our example, before a jury could find someone guilty of murder based on phrenological evidence (let’s say the State can prove that the defendant has the dreaded “murder bump” on his forehead) the State would have to show that phrenology is a scientific technique that is generally accepted in the scientific community. There would be a Frye-Mack hearing, and the State would fly in experts from around the world to testify about how everyone uses and respects phrenology, why phrenology is such good science, and maybe even why the specific bumps on their own heads prove that they are credible witnesses. If, after all the testimony, the judge is convinced that phrenology is generally accepted in the scientific community, the State has succeeded on “prong one” of the Frye-Mack test.

Frye-Mack Prong 2:  Did they do the test properly?

Having successfully met its burden on prong one, the State would then have to meet its burden on “prong two” of the Frye-Mack test. This second prong means that the State must not only show that a technique is generally accepted in the scientific community, but also that the laboratory conducting the tests in the individual case complied with appropriate standards and controls.

In our example, the State would meet its burden under the second prong of the Frye-Mack tests by presenting more experts that could show how phrenology typically works (probably with models of human skulls and demonstrations on how to use weird measuring devices). The State would then have to show that, in the case of our alleged murderer, those accepted techniques were used to conclude that yes, our alleged murderer does have the “murder bump” on his forehead, so of course he must be guilty.

Of course, in a real courtroom, a jury would never hear evidence of phrenology. That’s why Minnesota uses the Frye-Mack standard - to prevent the jury from even being exposed to junk science. In our example, I doubt a prosecutor could find one reliable expert that could sit in court and say, with a straight face, that the scientific community generally agrees that phrenology is valid science. Without proof of general acceptance in the scientific community, the State fails to meet its burden under prong one of Frye-Mack analysis and the evidence is excluded as junk science. We can all breathe a small sigh of relief knowing that the lumps on our head won’t lead to criminal charges in the near future.

However, the two prongs of the Frye-Mack test apply not just to phrenology, but every type of -ology, up to and including every type of mechanical or physical scientific test. Both prongs of the test, general acceptance and foundational reliability, must be met before scientific evidence can be presented to a jury.

DNA evidence, for example, has already been proven to be generally accepted at a Frye-Mack hearing, and juries now see this type of evidence every day. Polygraphs (lie detectors), on the other hand, have not been shown to have gained general acceptance in the scientific community, and until that happens in Minnesota, the results of polygraph tests cannot be presented to a jury.

The list of types of scientific evidence that has undergone the scrutiny of the Frye-Mack test is long, but every scientific technique that has been analyzed has one thing in common - the State had its chance to prove that the technique had gained general acceptance in the scientific community, and either succeeded or failed in its showing.

This, in a nutshell, is what a Frye-Mack hearing is - a special evidentiary safeguard that is in place to make absolutely sure that a person can’t be proven guilty based on science, unless and until that type of science has gained general acceptance in the scientific community.