Police turn away volunteers in Nancy Guthrie search due to evidence concerns

In Tucson, Arizona, police are reportedly turning away volunteer search groups looking for Nancy Guthrie. Former NYPD Lieutenant Darrin Porcher explains this controversial decision, stating that untrained volunteers can inadvertently corrupt evidence or compromise the chain of custody, which is crucial for court proceedings. He highlights the importance of proper evidence handling, such as using paper bags instead of plastic for DNA, to avoid contamination.