Earlier this week an article circulated via UPI talked about an evolving test that Massachusetts prosecutors will undoubtedly be using to help prove their cases. X-ray photoelectron spectroscopy, commonly referred to as XPS, looks at individual cotton fibers that contain distinct chemical traces on their surface. The chemicals are used in the treatment and manufacturing process of cotton garments. The XPS process helps to distinguish cotton fibers that through microscopic examination were thought to be indistinguishable. The chemicals in question are used to make the clothing article wrinkle free, resistant to staining or waterproof. Through XPS these chemicals can be identified on the surface of the individual fibers.
I imagine that once XPS testing is “perfected” this science will become prevalent in Massachusetts courts, particularly in serious felonies being prosecuted in the superior courts. I say this even though I do not believe that using XPS experts will be beneficial to the district attorney. Here is why. Prosecutors will want to test fibers to see if a match can be made to clothing worn or owned by the accused. At least initially, if there is a match there will be an argument that this link to the defendant corroborates other evidence in the case. This strategy will ultimately appear desperate. In general the fibers we are talking about and their processing and manufacturing treatments are not typically unique. Clothing is mass manufactured. In many cities it is common for youth to be wearing the same or similar clothing made by a particular company. For instance, for years black hooded sweatshirts made by a particular sporting goods company were the wardrobe of choice in certain parts of Boston and other major cities. You could walk down the street and see scores of youth wearing the same articles of clothing, same make and same logo. So how then does this more effectively link a particular defendant to a crime scene? It probably doesn’t and defense lawyers will quickly pick up on this as a challenge to the significance of this evidence.
Then why would prosecutors get into XPS testing at all? The trend among prosecutors in Massachusetts for more than a decade now is to introduce evidence known to have little significance if they believe that the defense will comment on its absence otherwise. For example, in murder cases where DNA is not an issue a prosecutor may nevertheless call a DNA expert to testify that certain evidence could not be tested for DNA. The same logic applies to fingerprinting and testing blood samples. So, once XPS testing becomes a household term we will see prosecutors, through their expert witnesses discussing this process. This will apply whether or not XPS testing was done and regardless of the test results. Thus, it will be important for Massachusetts criminal defense lawyers to familiar themselves with this process whether or not they use it.