It is the burden of the state to prove their case, and often they can rely on that evidence to get a conviction. The problem with evidence, and junk science, is that it is not subject to confirmation by peers. However, at a trial, an expert can say pretty much any outlandish thing that comes to mind. An attorney questioning an expert witness needs to understand as much of the science as the person testifying so that he can lead the expert to understand the logical flaw in his testimony- and make the distinction with his own expert.
In the United States Coast Guard v. Solomon, complex issues of chemistry lead to the suspension of her merchant mariner credentials due to a random urinalysis test in Dubai. After 5 years and two appeals, the National Transportation Safety Board overturned the suspension and awarded fees against the United States Coast Guard. The same argument that convinced the NTSB that Ms. Solomon was innocent was made by attorney Syfert within the first ten days of being hired based on his knowledge of chemistry. Two experts hired by Syfert explained that the results of the urinalysis could possibly be consistent with high temperatures of the desert.
A background in biology and medicine, Mr. Syfert has handled hundreds of personal injury cases, and hundreds of depositions involving injury. Nothing is more fun than an innocent person being exhonorated because of science!