Compelling evidence could lead to a conviction in a Pennsylvania criminal courtroom. Video footage, blood samples, and eyewitness testimony may come together to paint a picture of guilt. Hair samples might enter into evidence, sometimes swaying guilty verdicts. However, like other examples of forensic evidence, a hair analysis is not always perfect. A defendant may challenge questionable evidence to avoid a wrongful conviction.
Concerns about hair analysis evidence
Modern steps for hair analysis determinations rely on DNA. A laboratory analysis relying on mitochondrial DNA testing could provide far better results than a microscopic analysis. A microscopic hair analysis approach involves looking at the hairs under a microscope and making a judgment based on expertise.
Even an expert analyst could make a mistake, though. A false 1980 murder conviction relied on an analyst’s testimony that implicated an innocent man. Later DNA testing revealed some hairs belonged to a dog and none to the convicted person.
The microscopic analysis approach continues today, even though there could be problems with the procedure. Unfortunately, a jury could assume that microscopic analyses are always accurate, which is not necessarily the case.
Challenging the evidence
Hair becomes collected evidence at many crime scenes because people lose hair throughout the day. A criminal defense strategy could involve casting doubts on the analysis.
If there were errors committed with evidence collection, the defense might attempt to suppress it. Keeping the evidence out of the trial may severely damage the prosecutor’s case.
Those falsely convicted due to misidentified hair samples may seek to overturn the conviction on appeal. Some cases might result in a new trial that works more in the defendant’s favor.