The intersection of science and the law is interesting.
When DNA testing was in its infancy, there was a period when scientists knew they could reliably match biological samples to people to a vanishingly small error rate. And lawyers - defense lawyers, mostly - were arguing that the results should not be heard in court, because they were unreliable.
There are two different tests used in the United States judicial world to govern the admissibility of new scientific tests, methods, or techniques. In the federal system and many states, the Daubert test reigns. Based on Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), it’s a relatively lenient standard that grants the trial judge a fair degree of latitude in admitting evidence. Basically, if “scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise…” in other words, the judge can permit an expert to testify about his theory, period.
There is a more restrictive standard, and Florida uses it: the Frye standard, based on Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). This standard requires:
[ol]
[li]The trial judge must determine whether the expert testimony will assist the jury in understanding the evidence or in determining a fact at issue (same as Daubert)[/li][li]The trial judge must decide whether the expert’s testimony is based on a scientific principle or discovery that is “sufficiently established to have gained general acceptance in the particular field in which it belongs.”[/li]
[li]The trial judge must determine whether a particular witness is qualified as an expert to present opinion testimony on the subject at issue [/li][li]The judge may then allow the expert to render an opinion on the subject of his or her expertise, and then it is up to the jury to determine the credibility of the expert’s opinion, which it may either accept or reject.[/li][/ol]
From Ramirez v. State, 651 So. 2d 1164 (Fl. 1995).
So the key difference: Frye requires that the science to have reached a stage of general acceptance in its field — basically, that it not be novel or controversial. Daubert merely requires that an expert can be found and qualified to explain it.